Verinata Health, Inc. is
proud to offer the verifi™
prenatal test — a non-invasive prenatal test that detects
multiple fetal chromosomal aneuploidies using a single maternal
blood draw with near-diagnostic accuracy. If you have ever wanted
safer, simpler test results or wished to screen at 10 weeks
instead of waiting, now you can — order the verifi™ prenatal test.
Noninvasive
Prenatal DNA Test Okay for Low-Risk Pregnancies [2/27/14]
Early testing was done in high-risk women. This newest
research shows that the test is similarly accurate in low-risk
women.
Screening
for
Fetal
Chromosomal
Abnormalities Reviewed - this Medscape article offers
a fabulous overview of available testing as of January, 2009.
Pregnant
Women
In
The
Dark On Prenatal Screening - Soon-to-be mums admit they feel
'left in the dark' when it comes to being told about the possible
implications of prenatal screening - tests which could lead them
down a path where they have to make difficult decisions about
their unborn child.
NEW for 2007! - Down
screening
urged
for
all pregnant women - There's a big change coming for
pregnant women: Down syndrome testing no longer hinges on age
35. The newest method, topping ACOG's recommendation for
everyone, is a
first-trimester screening that combines blood tests with a
simple ultrasound exam, called a "nuchal translucency test" to
measure the thickness of the back of the fetal neck.
National Society of Genetic Counselors
Genetic counseling is the process of helping people understand and adapt to the medical, psychological and familial implications of genetic contributions to disease.
This process integrates:
* Collection and interpretation of family and
medical histories to assess the chance of disease occurrence or
recurrence
* Education about inheritance, testing,
management, prevention, resources and research
* Counseling to promote informed choices and
adaptation to the risk or condition.
BabyCenter.com
has
a
nice
web page to help parents learn about genetic counseling and
prenatal screening choices. It contains some nice
information about values clarification and why you might choose
prenatal screening even if you wouldn't consider terminating a
pregnancy.
Prenatal Diagnosis - a
comprehensive overview from Web pages of Greggory R. DeVore, MD -
Fetal Medicine
These Web pages include information about Genetic Ultrasound
Services, i.e. the use of ultrasound to detect Down
syndrome, and compares it to the use of the Triple Marker
Screening.
Risk of prenatal CVS same as amniocentesis: study - "Both procedures carry a small risk of miscarriage, but the study found that the risk attributable to CVS is the same as the risk of 1 in 370 seen with amniocentesis when adjusting for the earlier gestational age of the CVS procedure."
Chorionic
Villus
Sampling
Compared
With Amniocentesis and the Difference in the Rate of Pregnancy
Loss.
Caughey AB, Hopkins LM, Norton ME.
Obstet Gynecol. 2006 Sep;108(3):612-616.
CONCLUSION: The loss rates for both amniocentesis and CVS at our
institution have decreased over time. Because the decrease in loss
rate for CVS has been greater, there is no longer a statistically
significant difference between the two. These results are
informative in both patient counseling and establishing widespread
prenatal diagnostic and screening programs. LEVEL OF EVIDENCE:
II-2.
Fetal
nuchal
translucency
scan
and early prenatal diagnosis of chromosomal abnormalities by
rapid aneuploidy screening: observational study.
Chitty LS, Kagan KO, Molina FS, Waters JJ, Nicolaides KH.
BMJ. 2006 Feb 25;332(7539):452-5.
CONCLUSIONS: In the diagnosis of chromosomal abnormalities after
first trimester screening for trisomy 21, a policy of qf-PCR for
all samples and karyotyping only if the fetal NT thickness is
increased would reduce the economic costs, provide rapid delivery
of results, and identify 99% of the clinically significant
chromosomal abnormalities.
Prenatal
Testing from americanpregnancy.org
Test
Detects
Down
Syndrome
Early - Screen relies on fetal neck width at 11 weeks, plus
maternal blood protein levels
1st
Trimester Ultrasound Scanning and similar
web pages
As of July, 2005, Quest Diagnostics offers:
Maternal Serum Screen 5 is a new prenatal screen for neural tube defects, Down syndrome, and trisomy 18. The screen includes invasive trophoblast antigen (ITA), a hyperglycosylated form of hCG, and 4 other markers. Early studies indicate that addition of ITA improves the Down syndrome detection rate.
Maternal
Serum
Screen,
1st
Trimester is a new prenatal screening test for Down syndrome
and trisomy 18. The test includes PAPP-A, ITA, and nuchal
translucency (NT).
Prospective
first-trimester
screening
for
trisomy 21 in 30,564 pregnancies.
Avgidou K, Papageorghiou A, Bindra R, Spencer K, Nicolaides KH.
Am J Obstet Gynecol. 2005 Jun;192(6):1761-7.
CONCLUSION: The most effective method of screening for chromosomal defects is by first-trimester fetal NT and maternal serum biochemistry.
"In summary, "the detection rate of trisomy 21 and other major chromosomal defects by this method was about 90 percent, for a false-positive rate of 5 percent," write Avgidou et al."
ACOG
Supports First-Trimester Screening for Fetal Aneuploidy -
First-trimester screening is a viable method of detecting fetal
aneuploidy. Moreover, the approach offers several possible
advantages over second-trimester screening, according to a
position statement released by the American College of
Obstetricians and Gynecologists (ACOG). [6/30/04]
OK - I'm sorry . . . I can't take the hypocrisy any longer. Now that doctors are getting serious competition from "entertainment ultrasound boutiques", suddenly they're talking about how dangerous ultrasound is. Is it only dangerous if the money's going to someone without an MD? What about routine ultrasound, which has been shown NOT TO BE BENEFICIAL in the absence of complications that are obvious from a clinical point of view, i.e. too much or too little amniotic fluid, baby not growing well, ruling out multiples, postdates, etc.?
For an overview of this issues, see 4-D
Ultrasounds
Are Risky Entertainment from Dr. Mercola's site.
All those false positives from the MS-AFP or triple screen and the long wait for the results of the amniocentesis significantly increase a woman's anxiety level. Here's how those can cause problems later on:
Anxiety
in
Pregnancy
Ups
Kids' Behavioral Problems [Fri Jul 16, 2004 02:16 PM ET
By Alison McCook ]
"Women who are chronically stressed out during the middle of a
pregnancy are more likely to give birth to children who develop
behavioral problems later in life. . . . The investigators found
that women who were very anxious between the 12th and 22nd weeks
of their pregnancies were more likely to have children who were
also anxious and showed symptoms of attention
deficit/hyperactivity disorder (ADHD)."
Janet Robinson published an article around 1999 in BJM or Practicing Midwife from a study based on interviews w. women who had serum screen positive for Downs and went on to deliver a normal baby. Some of these women described lingering concerns about their baby's well-being, including an assumption that their infant was more vulnerable.
Speaking the
Language of Genetics: A Primer [Medscape registration is
free]
Pre-natal Diagnosis - Making Difficult Decisions, by Sarah J. Buckley, MD, from Women of Spirit
This is a fabulous article from Mothering Magazine:
Prenatal
Testing
and
Informed
Consent: Base Your Choices on the Evidence
By Peggy O'Mara
Issue 120, September/October 2003
In consideration of prenatal screening it is important to keep in mind that there is NO BENEFIT to the baby, only the actual harm of the invasive tests such as ultrasound and amniocentesis, and the potential of harm if the results aren't what the parents are hoping for. Prenatal screening is generally used as a means of finding out if the baby is good enough or perfect enough to be allowed to live. This kind of "tentative pregnancy" has ill effects on all tested babies, even those who are deemed good enough to be allowed to live. (For more information about how a tentative pregnancy affects a fetus "in utero" and later throughout life, familiarize yourself with the work of APPPAH.)
Becoming a parent is a very serious matter, and if you cannot live with any child who is less than perfect, well, then, maybe you want to give some thought to the commitment one makes in choosing to become a parent. If you can't accept and love a baby born with developmental problems, what will you do if your child develops problems later in life? What will you do if your child is autistic or develops juvenile diabetes or leukemia or is disabled in an accident? If your children don't disappoint you before you are born, you can generally bet that they will at some time disappoint you after they are born. It takes tremendous maturity and responsibility to accept that in choosing to become a parent, you are offering to satisfy humanity's drive to propagate the species, and that your role as a parent is to serve the child, not the other way around.
Still, raising a child with developmental problems is a great
deal of responsibility to take, and I'm sure there are babies who
are better often being "terminated" than being born into a family
that cannot love them because of their perceived
shortcomings. If this is your situation, please at least
have the decency not to say that you are doing genetic screening
for the baby's sake.
Actually, I have to disagree that prenatal screening confers no
benefit to the baby. Research indicates that parents who
know in advance that their baby may have problems are better
prepared and thus better able to be the best possible parents to
these babies. "Women who have delivered a child with a
chromosomal aneuploidy, such as trisomy 21, are more satisfied
with the outcome of their pregnancy when they learn of their
child's diagnosis before delivery." [from Pregnancy
Outcomes
After
Prenatal
Diagnosis of Aneuploidy - Medscape registration is free]
I also disagree. There are some very rare conditions which
need immediate treatment at birth in order to save the child's
life.
Yes, there may be some very rare conditions which might benefit
from prenatal diagnosis, but we need to look at the risk/benefit
ratio. The Cochrane Collaboration has done separate reviews
of routine
early and late
ultrasound and found that neither has a clear benefit to
either mother or child. A crystal ball would allow us to
screen only the very rare cases where the benefits are greater
than the risks.
Chorionic
Villus
Sampling
and
Amniocentesis: Recommendations for Prenatal Counseling from
the CDC
Evidence
based
screening for Down's syndrome. We should be prepared to
re-examine entrenched practices. [Medline
entry]
Raeburn S
BMJ 2000 Mar 4;320(7235):592-3
Medscape has a nice commentary:
Screening for Down's syndrome based on maternal age and routine ultrasound testing is considerably more effective than assumed, according to a report in the March 4th issue of the British Medical Journal.The results call into question the widespread use of serum screening for Down's syndrome, according to the study's lead author. "If you asked most obstetricians about the evidence for serum screening, I am sure that they would tell you that the case for its use was unassailable," the study's lead author, Dr. David T. Howe, of the Princess Anne Hospital in Southampton, England, told Reuters Health. "In fact, there has never been a controlled study of its effectiveness anywhere in the world."
Sheila Kitzinger on Ultrasound - A very
nice piece by Sheila Kitzinger, excerpted from Rediscovering
Birth.
Information about the legal obligations of California
practitioners regarding prenatal genetic screening.
SOFT provides support for
families affected by Patau's syndrome (trisomy 13), Edwards'
syndrome (trisomy 18), partial trisomy, mosaicism, rings,
translocation, deletion, and related disorders.
Prenatal
Screening - Interpretation of Results
Genetic
Screening Methods from Creighton University School of
Medicine
Screening in
pregnancy - written for parents
New 'Integrated' Prenatal Screening Test Can Detect 90% of Down Syndrome Cases With 5% False-Positive Rate [Feb 09, 2004]
A new prenatal screening test that carries no risk to the fetus
can detect 90% of Down syndrome cases, but the test has a 5%
false-positive rate and pregnant women must wait until the second
trimester of pregnancy to receive the results, according to a
study presented on Thursday at the Society for Maternal-Fetal
Medicine Conference in New Orleans, the Wall Street Journal
reports. The "integrated screen" test -- which combines
information from a first-trimester ultrasound and blood tests
conducted in the first and second trimesters -- "is creating
excitement and controversy," according to the Journal. Researchers
conducted the integrated screen on 33,557 pregnant women at 15
centers nationwide. The test correctly identified 90% of Down
syndrome pregnancies but falsely identified the condition in 5% of
the women tested. If researchers defined a positive result
slightly different, false alarms would have occurred in only 1.4%
of the women, but the positive detection rate for Down syndrome
cases would have fallen to 80%. Women who test positive are
offered an amniocentesis, a procedure in which a doctor inserts a
needle into the pregnant woman's uterus to obtain fluid from the
amniotic sac. Although amnios are almost 100% effective in
detecting Down syndrome cases, they carry a small risk of
miscarriage. With the integrated test, many women can avoid the
invasive tests. The test "seems to be the most efficient screen"
and "is associated with a lower need for amnio" than other
screening procedures, Mary D'Alton, a Columbia University
scientist who served as principal investigator in the trial, said.
The test has created controversy among some obstetricians because
women are not informed of their test results until the second
trimester, which is a late stage for women who decide to terminate
the pregnancy, according to the Journal (Johannes, Wall Street
Journal, 2/6/04).
Blood Test for Down's Syndrome in First Trimester
Maternal Blood Test Can Detect Down's Syndrome in Fetus [Medscape registration is free.]
Update
on
Preconception
and Prenatal Carrier Screening for Cystic Fibrosis [Medscape
registration is free]
See also: Placenta
Previa/Placenta Location
The white spot on the heart is called echogenic intracardiac
focus and usually means there's a calcification of one of
the papillary muscles. It is found in about 7% of ultrasounds at
13-16 weeks and 3% at 20-22 weeks (the incidence can be as high as
30% in Asians).
Implications:
Noted to be present in 25% of Downs Syndrome fetuses and 5% of
normal fetuses. The risk of Downs Syndrome in a fetus with
echogenic intracardiac focus in about 0.002%.
Follow-up:
Karyotyping is not warranted. The risk of amnio far
outweighs the risk of Downs in a low risk population. They
usually resolve spontaneously and babies are born normal. Pt
may choose to have triple marker screen. Patients may
be referred to genetics for counseling if exceptionally anxious
about this finding.
Renal Pelviectasis/Pyelectasis:
Definition:
A mild dilation of the fetal renal pelvis. It is found in
approximately 2% of normal fetuses. It has been defined as
>4mm before 33 weeks and >7mm after 33 weeks.
Implications:
Can sometimes be associated with obstruction and can lead to
hydronephrosis. The severity of pyelectasis may predict the
development of hydronephrosis and possible postnatal
complications. While not an independent predictor,
pyelectasis has also been found to be present in 15-25% of fetuses
with Downs. Other reasons that lead to hydronephrosis are:
physiologic, uretropelvic junction obstruction, vesicocoureteral
reflux, multiplastic kidney, posterior urethral valves, and
ureterocele/ectopic ureters. *But usually it is physiologic
(ie fetus needs to pee!).
Follow-up:
A follow-up ultrasound should be done in 6-8 weeks. Most
often it will have spontaneously resolved. If it is still
present but less than 6mm the baby will be followed with
ultrasounds 48 hours after birth and 3 months and after if
needed. If greater than 6mm the baby will be put on
prophylactic antibiotics and be followed by ultrasound at 48
hours. Depending on the result (if there is a pathological cause
for this) the baby may need additional testing and continued
antibiotics. It usually resolves spontaneously by 3 months.
Standard Down's screen topped by early alternative
First-trimester
or
second-trimester
screening,
or both, for Down's syndrome.
Malone FD et al.
N Engl J Med. 2005 Nov 10;353(19):2001-11.
"Our results demonstrate that first-trimester screening for Down's syndrome is highly effective," state the authors of an article published in the November 10, 2005, issue of the New England Journal of Medicine. Accurate comparison of the performances of different screening tests conducted at different times during pregnancy remains complex owing to concern about spontaneous pregnancy losses that may occur between first- and second-trimester screenings. The article presents findings from the First- and Second-Trimester Evaluation of Risk (FASTER) Trial with the goal of providing direct comparative data on currently available screening approaches for Down syndrome from a large population followed prospectively.
The study was conducted at 15 centers from October 1999 to December 2002. Participants included adolescents and women ages 16 or older pregnant with a singleton fetus with a gestational age at study entry ranging from 10 weeks, 3 days through 13 weeks, 6 days. Following an initial screening and risk assessment (adjusted for maternal age) during the first trimester, participants returned at 15-18 weeks gestation for second-trimester screening and risk assessment. Performance characteristics of screening tests for Down syndrome were estimated with first-trimester markers measured at 11, 12, and 13 completed weeks of gestation and with second-trimester markers measured at 15 through 17 weeks completed weeks of gestation. The analysis compared first-trimester screening for Down syndrome with second-trimester screening (the current standard of care) and with screening in both trimesters.
Complete first- and second-trimester screening data were available for 33,459 unaffected pregnancies and 87 pregnancies affected by Down syndrome. At a 5% false positive rate, the rates of detection of Down syndrome were as follows:
* With first-trimester combined screening, 87% at 11 weeks, 85 % at 12 weeks, and 82% at 13 weeks.
* With second-trimester quadruple screening, 81%.
* With serum integrated screening (single serum marker in the first trimester and quadruple serum markers in the second trimester), 88%.
* With fully integrated screening, 96%.
"When there is appropriate quality control . . . first-trimester combined screening is a powerful tool for the detection of Down's syndrome," conclude the authors. They add that consideration of the advantages of earlier diagnosis, the costs associated with different strategies, and patient preferences will help guide the choice between approaches.
Malone FD, Canick JA, Ball RH, et al. 2005. First-trimester or second-trimester screening, or both, for Down's syndrome. New England Journal of Medicine 353(19):2001-2011. Abstract available at http://content.nejm.org/cgi/content/short/353/19/2001.
Antenatal
screening
for
Down's
syndrome - Nuchal translucency plus biochemical tests has
the lowest false positive rate Alfirevic Z, Neilson JP. BMJ.
2004 Oct 9;329(7470):811-2.
I have just finished reading the fabulous book Down Is Up for Aaron Eagle : A Mother's Spiritual Journey With Down Syndrome, written by Vicki Noble about her special son. She reports that in many cultures, people with Down Syndrome are regarded as shamans, healers or other special people of value to their community. She also highlights the observation that we might regard Down Syndrome as a positive mutation, as those with Down Syndrome are often more peaceful, amiable and generally likable human beings.
I was intrigued by her observations that Down Syndrome is in some
ways a disease of elimination, and that special attention to
facilitating elimination and maintaining overall good health can
support an expanded potential. Then the thought occurred to
me that perhaps Down Syndrome is like phenylketonuria - a
metabolic disorder that causes brain damage as a side effect of a
primary metabolic problem. What if we discovered that Down
Syndrome is a treatable metabolic disorder like
phenylketonuria? What if a special maternal diet could
prevent the brain damage that is typically seen in newborns with
Down Syndrome? What if we could somehow support this human
mutation to be all that it could be . . . a more peaceful human
being with extra abilities gifted from the extra chromosome?
Recent
developments
in
fetal
medicine. [full
text]
Kumar S, O'Brien A.
BMJ. 2004 Apr 24;328(7446):1002-6.
Womb
surgery
rescues
Womb
surgery rescues severe CDH cases
Source: Ultrasound in Obstetrics and Gynecology 2004; 24: 121-6
Fetal
surgery [BMJ 2003;326:461-462 ( 1 March )]
Fetal
medicine
or
surgery as alternatives to abortion - Even parents who are
opposed to abortion may consider prenatal testing as a way of
identifying situations where prenatal surgery might result in a
healthy child.
UCSF's Fetal Treatment Center FAQ
Fetal
Surgery
Offers
Hope
- Operating in the womb for spina bifida
Early screening for Down, cystic fibrosis [July 17, 2003]
Researchers have created a prenatal test that detects Down syndrome and cystic fibrosis as early as five weeks after conception. The new test is based around PAP smears of the type normally taken for cervical cancer screening, and it can yield results the same day.
Scientists have known for years that fetal cells can be found in the cervix. However, this is the first time such cells have been efficiently isolated from cervical smears.
According to the researchers, the cells are DNA fingerprinted to distinguish the mother's own cells from the fetal cells. Then they test the fetal cells for genetic abnormalities using single cell DNA detection, new technology that uses smaller cell samples than chorionic villus sampling (CVS) or amniocentesis.
"They can take a single cell and expand the DNA and analyze it, as opposed to the previous techniques, when multiple cells had to be cultured and grown [in a laboratory] before you could get enough DNA to do an accurate test."
The lead researcher is Ian Findlay, of the Australian Genome Research Facility.
This test could be generally available within 2 years.
It's very hard to find the normal
value for different markers in the MSAFP / Quad Screen.
Many of the state-run screening programs don't want people
interpreting their own results.
Fetal Indications Termination
of Pregnancy Program
ACOG
Issues
Educational Bulletin on Maternal Serum Screening
False Positive Rates
Year 2000 statistics from California Dept. of Health Services - Genetic Disease Branch - 510-540-2534 [Statistics from previous years]
Screen positive reates for inital test results:
I believe that ACOG recently replaced their "bulletin" about MSAFP with a triple screen bulletin. I feel that the cost differential is very worthwhile. But, what is a cost differential? Often these are artificial. In Iowa the state program is automatically the triple screen for about $70 which is less than many companies charge for afp alone. I think the same is true for the large California program where the cost of testing of abnormals (amnio, sono) is factored in. The differential in average detection will be 25% of Downs for AFP alone to about 60% for the triple screen.
For reasons above I personally consider triple screen to be
standard of practice. Women over 35 (as with all patients) should
discuss their options of invasive testing right off the bat (amnio
or CVS), triple screen (understanding the number of missed cases,
but also the high chance they will be down screen positive because
age is factored in. I think about 25% of 35 year olds will be
screen positive.), and ultrasound (also will miss many cases),
etc. My experience is that patients are often steered to a
particular course by a physician's preference but I think the
patient deserves a pretty full explanation and then should make
the decision herself.
If you screen all your patients (incl. < 35) with
double/triple test your false positive rate must increase (the 60%
pick-up rate applies only to maternal age > 35).
NOT TRUE!!
It is well documented that the Down syndrome prenatal detection rate of 60% for a false positive rate of 5% is a common finding when triple screening is offered to women of ALL ages, not just those over 35 (see Palomaki et al. in J Med Screening, 1996, 3: 12-17).
The false positive rate and the detection rate will vary, depending on the age distribution of the screened population. In women over 35, the detection rate is close to 90%, with a false positive rate of 25%. Therefore, 75% of patients over 35 will be informed that their risk is below the risk cut-off for consideration of amniocentesis (in North America, usually that of a 35.5 year old).
If triple screening is available to women of all ages, and if there is close attention to communicating the results of the screen to patients such that the patients understand their own risk (instead of a general population risk like "women over 35"), the amniocentesis rate will diminish. Why? Because the false positive rate of the triple screen is always lower than the percentage of pregnant women who are over 35.
Returning to the original question, is triple screening justified
over MSAFP, the answer is "yes". In addition to the studies in the
reference quoted above, we just reported our detection of Down
syndrome in 10,540 screened women (median age 29.4 years) using a
risk cut-off of 1:385 with a false positive rate of 8%. Of 21
cases at mid-trimester, maternal age detected 6 (29%), age+MSAFP
detected 8 (38%), age+AFP+hCG (the "double" screen) detected 12
(57%) and age+AFP+uE3+hCG (the "triple" screen) detected 15 (71%).
Approximately 11% of our population is over the age of 35
(possible 11% amniocentesis rate); however, the amniocentesis rate
for ALL reasons was only 8%.
Amniocentesis - Search & Destroy by Dave Stewart of NAPSAC-
link temporarily unavailable
PanoramaScan.com - The
Ultimate Ob/Gyn, 2D, 3D/Live 4D Ultrasound Source Online - This
web site is dedicated for eager-to-learn gynecologists,
obstetricians, sonologists and sonographers who want to obtain a
huge amount of information about gynecological and obstetric
ultrasound (Ob/Gyn ultrasound) , whether a 2D scan or a 3D/4D real
time scan. Browse the huge library of ultrasound images, videos,
documents and presentations for any obstetric ultrasound,
gynecological ultrasound, basic embryology (sonoembryology) and
fetal therapy ultrasound subject.
A Comprehensive Guide to
Obstetric Ultrasound by Joseph Woo
Preg.info - Ultrasound
Scan Information - Information about the goals of
ultrasounds at different points in pregnancy
Prenatal
Ultrasound from The International Chiropractic Pediatric
Association (ICPA)
What
is
Ultrasound?
A
Definition of its Use and Practice [from Mothering Magazine]
Elizabeth Bruce explains how ultrasound
works and what the indications for its use are.
"The results show that we can be accurate with prediction of
gestational age within seven days between 14 and 20 weeks, within
10 days between 21 and 28 weeks, and within 17 days between 29 and
40 weeks," Dr. Daniel W. Skupski, from New
York-Presbyterian/Queens in Flushing, New York, told Reuters
Health by email.
Misinformation Surrounding Fetal Weight Estimation and Due-Dates -- Enough to Make Anyone Grumpy. Linda Johnson explains why...
I wonder what the docs and US techs think about Hadlock. He was the physician who figured out the measurements for fetal parts such as the biparietal diameter, femur length, etc. should be for the various gestational ages. His premise was that for an average size baby (7-7.5 lbs), these are the average measurements. There are actually 26 or more algorithms for determining fetal weight/size. A good link with really technical/statistical stuff is Estimation of Fetal Weight from emedicine.com or google fetal biometrics.
All of these measurements are based on averages of babies from the 10th-90th percentile for that gestational age, but whether it is ethnically and racially representative may be questionable. (Think the average Vietnamese vs. Swedes). If you have a baby that will have long legs and probably be tall as an adult, then the femur length will probably be in the 90th percentile and your baby will be predicted to be macrosomic. If you have babies with smaller heads (10th percentile) then the baby will probably be predicted to be IUGR.
Now if those measurements are used as the basis for determining the due date because the docs just don't believe the mom, a baby that is smaller will be assumed to not be as far along in the pregnancy because all babies will be 7-7.5# at birth (please note the sarcasm there). The opposite is true with a baby that will be long. It appears to be due sooner. None of that changes when conception occurred or when term occurs (37-42 weeks).
Changing the due date based on the US measurements shows a very
basic misunderstanding of the limits of US, the statistical
significance of the algorithms, and the expertise of the US tech.
Parameters
for
Ultrasound
Exams
in Pregnant Women [Medscape registration is free]
Placenta-Grading
by Tara Herzberg, MD
Cochrane Collaboration Abstracts:
* Ultrasound
for
fetal
assessment
in early pregnancy
* Routine
ultrasound
in late pregnancy (after 24 weeks gestation)
OB-GYN Ultrasound Online
- An Interactive Text and Journal
Ultrasound in
Pregnancy, Infertility and Gynecology and General Ultrasound
- a wealth of information, albeit somewhat overly enamored of
technology. This site has a large page called ultrasound in
pregnancy web book
Obstetrical
Ultrasound Measurements - nice tables of gestational age and
typical measurements
Subject: Embryonic Heart Activity
Question: what is the normal embryonic heart
rate
Answer: Embryonic Heart Rate
The cutoff CRL for detecting cardiac activity by transvaginal
probe is 4 mm, and by transabdominal 9 mm.
Heart rate progressively increases to 120-160 beats/minute after 6
to 7 weeks.
WASHINGTON (AP) -- Exposure to ultrasound can affect fetal brain development, a new study suggests. But researchers say the findings, in mice, should not discourage pregnant women from having ultrasound scans for medical reasons.
Ultrasound scans can affect brain development from CNN Health
"Rakic's paper said that while the effects of ultrasound in human brain development are not yet known, there are disorders thought to be the result of misplacement of brain cells during their development.
"These disorders range from mental retardation and childhood epilepsy to developmental dyslexia, autism spectrum disorders and schizophrenia," the researchers said.
"Their report is in Tuesday's edition of Proceedings of the National Academy of Sciences.
"The study of 335 mice concluded that in those whose mothers were exposed to a total of 30 minutes or more, "a small but statistically significant number" of brain cells failed to grow into their proper position and remained scattered in incorrect parts of the brain. The number of affected cells increased with longer exposures."
Ultrasound affects mouse brains from Reuters [8/9/06]
"The corresponding neurons in the human brain would probably be
formed in the 16th week and continue to migrate for at least 1-2
weeks," Caviness wrote.
Prenatal
exposure
to
ultrasound
waves impacts neuronal migration in mice.
Ang ES Jr, Gluncic V, Duque A, Schafer ME, Rakic P.
Proc Natl Acad Sci U S A. 2006 Aug 22;103(34):12903-10. Epub
2006 Aug 10.
"Neurons of the cerebral neocortex in mammals, including humans,
are generated during fetal life in the proliferative zones and
then migrate to their final destinations by following an
inside-to-outside sequence. The present study examined the effect
of ultrasound waves (USW) on neuronal position within the
embryonic cerebral cortex in mice. We used a single BrdU injection
to label neurons generated at embryonic day 16 and destined for
the superficial cortical layers. Our analysis of over 335 animals
reveals that, when exposed to USW for a total of 30 min or longer
during the period of their migration, a small but statistically
significant number of neurons fail to acquire their proper
position and remain scattered within inappropriate cortical layers
and/or in the subjacent white matter. The magnitude of dispersion
of labeled neurons was variable but systematically increased with
duration of exposure to USW. These results call for a further
investigation in larger and slower-developing brains of non-human
primates and continued scrutiny of unnecessarily long prenatal
ultrasound exposure."
From the Medscape article, Unnecessary Testing in Obstetrics, Gynecology, and General Medicine: Causes and Consequences of the Unwarranted Use of Costly and Unscientific (Yet Profitable) Screening Modalities by Martin Donohoe, MD, FACP [4/30/07]:
"Other monitoring tests may be misused. One example of this is
fetal ultrasonography. Although it is helpful in estimating
gestational age, identifying twin pregnancies, and detecting
genetic anomalies, the American College of Obstetrics and
Gynecology (ACOG) position is that routine ultrasonographic
screening during pregnancy is not mandatory."
Multiple Prenatal Ultrasound Examinations Do Not Hinder Child Development - Medscape analysis - [Medscape registration is free]
This study confirmed that multiple ultrasound scans cause a reduction in fetal growth that disappears statistically as the years pass.
For those who like to think critically, consider that "the control group" had a single ultrasound. I would personally like to see a control group that is not exposed to any ultrasound at all!
Also, despite findings of an increase in left-handedness among children exposed to repeated ultrasounds, this study does not appear to address that issue. And this isn't just about the inconvenience of being left-handed in a right-handed world; there was a study that claimed that right-handed people live, on average, nine years longer than left-handed people. This study has since been controverted, but it did raise some solid questions about how being left-handed endangers people in a world with tools and machinery built for right-handed people.
Effects
of
repeated
prenatal
ultrasound examinations on childhood outcome up to 8 years of
age: follow-up of a randomised controlled trial.
Newnham JP, Doherty DA, Kendall GE, Zubrick SR, Landau LL, Stanley
FJ.
Lancet. 2004 Dec 4;364(9450):2038-44.
"FINDINGS: Examinations were done at 1, 2, 3, 5, and 8 years of
age on children born without congenital abnormalities and from
singleton pregnancies (intensive group n=1362, regular group
n=1352). The follow-up rate at 1 year was 85% (2310/2714) and at 8
years was 75% (2042/2714). By 1 year of age and thereafter,
physical sizes were similar in the two groups. There were no
significant differences indicating deleterious effects of multiple
ultrasound studies at any age as measured by standard tests of
childhood speech, language, behaviour, and neurological
development."
Ultrasound Scans- Cause for Concern by Sarah Buckley, MD
[This is one of the free articles available from BirthLove -
Leilah McCracken's site. In general, this is a subscription
site - well worth the $10 membership fee.] [Ed:
birthlove.com is not available at this time.]
or a similar article - Ultrasound - Reasons for
Caution, by Sarah
J. Buckley, MD, from the section on Medical
tests
and
procedures at Women of
Spirit
British
Medical
Ultrasound
Society
- Guidelines for the safe use of diagnostic ultrasound equipment
ECMUS Safety
Committee Tutorial - Epidemiology of diagnostic ultrasound
exposure during human pregnancy
Obstetric
Ultrasound - The Safety References by Joseph Woo - Recent
Studies purporting to the safety of prenatal exposure to
diagnostic ultrasound
Read
the
FDA's
response
to a petition to have Doppler fetoscopes changed to an
over-the-counter status, rather than a controlled medical
device. "OTC purchase and use of Doppler fetoscopes by a lay user
raises new issues of safety and effectiveness. . . . These
products introduce acoustic energy into the body. The
potential for adverse effects from long-term exposure to the fetus
in early pregnancy are unknown. For example, there are some
studies that suggest exposure to diagnostic ultrasound during
pregnancy can have an effect on human development. (Keiler
et al., Early Human Development 50:233-245 (1998); Keiler et al.,
Epidemiology 12:618-623 (2001).) You may also be aware of
ultrasound bone healing devices that operate at frequencies and
output levels similar to those of ultrasound Doppler
monitors. These devices have been shown to produce
biological effects in humans when used for only 20 minutes daily.
(Duarte, L.R., Arch. Orthop. and Trauma Surg., 101:153-159
(1983).) The agency has concluded that unsupervised exposure
to ultrasound may pose a risk to the health of the mother or a
developing fetus. . . . FDA has seen no evidence that there are
benefits that would outweigh these possible risks associated with
OTC availability of fetal ultrasound devices. The materials
you have provided do not establish that OTC purchase and use of
these products would result in any medical benefit to the fetus or
the mother. FDA cannot rely upon the absence of
specific adverse events as a basis to determine that repeated,
prolonged, and unsupervised ultrasound is safe. . . . While
I agree that women want to hear their unborn babies, I do not
believe that consumers would purchase devices enabling them to
achieve that purpose if the device might potentially cause harm to
the fetus through uncontrolled and unlimited use."
Ultrasound linked to brain damage - Risk is 'only a possibility' but the discovery warrants further study, researcher says. "LONDON - Swedish scientists have uncovered evidence suggesting that ultrasound scans on pregnant women can cause brain damage in their unborn babies." [Dec. 10, 2001 - research scientist Professor Juni Palmgren]
Sinistrality-a
side-effect
of
prenatal
sonography: A comparative study of young men.
Kieler H, Cnattingius S, Haglund B, Palmgren J, Axelsson O.
Epidemiology 2001 Nov;12(6):618-23
"Although ultrasound during pregnancy is used extensively, there is little published on adverse fetal effects. We undertook a cohort study including men born in Sweden from 1973 to 1978 who enrolled for military service. We estimated relative risks for being born left-handed according to ultrasound exposure in fetal life using logistic regression analysis. Eligible for the study were 6,858 men born at a hospital that included ultrasound scanning in standard antenatal care (exposed) and 172,537 men born in hospitals without ultrasound scanning programs (unexposed). During the introduction phase (1973 to 1975) there was no difference in left-handedness between ultrasound exposed and unexposed (odds ratio = 1.03, 95% confidence interval (CI) = 0.91 to 1.17). When ultrasonography was offered more widely (1976 to 1978), the risk of left-handedness was higher among those exposed to ultrasound compared with those unexposed (odds ratio = 1.32, 95% CI = 1.16 to 1.51). We conclude that ultrasound exposure in fetal life increases the risk of left-handedness in men, suggesting that prenatal ultrasound affects the fetal brain."
See Related
Articles
Is it possible that ultrasound could cause the baby's head to harden, thus making birth more difficult?
Accelerated
healing
of
distal
radial fractures with the use of specific, low-intensity
ultrasound. A multicenter, prospective, randomized,
double-blind, placebo-controlled study.
Kristiansen TK, Ryaby JP, McCabe J, Frey JJ, Roe LR.
J Bone Joint Surg Am. 1997 Jul;79(7):961-73.
"We concluded that this specific ultrasound signal accelerates the healing of fractures of the distal radial metaphysis and decreases the loss of reduction during fracture-healing."
See Related
Articles
Diagnostic Ultrasound Imaging in Pregnancy - [THIS DOCUMENT IS NO LONGER VIEWED BY NIH AS GUIDANCE FOR CURRENT MEDICAL PRACTICE.] - National Institutes of Health Consensus Development Conference Statement. February 6-8, 1984
This is an old study, but it does a good job of describing the potential problems associated with ultrasound.
"A number of biological effects have been observed following
ultrasound exposure in various experimental systems. These include
reduction in immune response, change in sister chromatid exchange
frequencies, cell death, change in cell membrane functions,
degradation of macromolecules, free radical formation, and reduced
cell reproductive potential."
This is not just an amplifier, these are ultrasound devices. I
believe the use should be restricted and not supplied to the
general public. Most women having home or waterbirth also have
qualified attendants who are skilled at interpreting normal and
abnormal changes in FHT. If Jane Q Public is interested in FHTs, a
fetoscope is simple and easy to use. Perhaps not so sexy to those
who love technology ... but as far as I am concerned, normal birth
could use a lot less of that.
According to Anne Frye, midwife and author of "Understanding Lab Work in the Childbearing Year" (4th Ed.)p. 405:
Doppler Devices: Many women do not realize that doppler fetoscopes are ultrasound devices. (apparently, neither do many care providers. Time after time, women are assured by doctors and even some nurse midwives that a doppler is not an ultrasound device.) . . . .
Not well publicized for obvious reasons, doppler devices expose the fetus to more powerful ultrasound than real time (imaging) ultrasound exams. One minute of doppler exposure is equal to 35 minutes of real time ultrasound. This is an important point for women to consider when deciding between an ultrasound exam and listening with a doppler to determine viability in early pregnancy. . . . .
If you have a doppler, put it aside and make a concerted effort to learn to listen yourself! Save your doppler for those rare occasions when you cannot hear the heart rate late into pushing or to further investigate suspected fetal death. " copyright l990, Anne Frye, B.H. Holistic Midwifery.
Personally, after 23 years of attending births, I would not
permit a doppler in my house if I were pregnant. You always
know that something is ultrasound because there will be "jelly"
involved. If you want a cheap listening device for the
baby's heart just save the core from a roll of toilet paper. Put
one end on the lower belly and the other on hubby's ear. If
you want to know your baby is doing well, count the fetal
movements in a day. Starting at 9 a.m. count each time the
baby kicks. There should be l0 distinct movements by 3 p.m.
I have a friend who's a chiropractor/homeopath. He uses kinesiology to evaluate well-being and select remedies. He related a story of one of his clients, who came in for an appointment very early in her pregnancy and then a few weeks later, after the first prenatal appointment. My friend said that his evaluation of the fetus at the first appointment was that it was very healthy, but it had been traumatized by the second appointment. His best guess was that the ultrasound had been a very traumatic event for the baby.
This has given me some food for thought; after all, what do we
really gain by routinely using hand-held Dopplers to listen to the
baby's heartbeat? If there's no question of dates, it
doesn't give us any information that will help this mother and
baby to have a healthier pregnancy.
Even later in pregnancy, if we're concerned about the baby's
well-being, it's easy enough to listen with a fetoscope or even
just with your ear! I'm sure that's much less traumatic
for the baby.
Weighing
the
Risks: What You Should Know About Ultrasound [from Mothering Magazine]
Examining the risks, benefits and
implications of the practice, Sarah Buckley questions if routine
ultrasounds should be a part of most pregnancies.
Ultrasound -
weighing the propaganda against the facts
Prenatal
Ultrasound Tied to Autism Severity in At-Risk Kids [9/21/16]
by Megan Brooks
The sounds the fetus hears in the uterus during ultrasound procedures.
Spectral
characteristics
of
the
sound generated by ultrasound imaging systems in the human body.
Here's some web links re the dangers of ultrasound. Don't use a doppler without giving this informed consent info.
Good/bad site. has some research results in it. Bioeffects of
ultrasound studies 1980-1990
Studies in the
1980s and 90s purporting to the safety of prenatal exposure to
diagnostic ultrasound:
Dyslexia : "In the first, Stark et al examined 425 children aged 7-12 who had antenatal exposure to ultrasound and 381 matched children who had not. They looked at 16 outcomes, one of which was dyslexia as measured by a single reading test and concluded that there was a significant correlation (p less than 0.01)." Non-right handedness "TI-le same Norwegian study did find a correlation between ultrasound exposure and non-right-handedness. 19% of the exposed children were non-right handed as compared with 15% of the controls. Although this result has been reported as significant, the correlation is relatively poor and is now the subject of ongoing research by the same group." "The meta-analyses of randomised controlled trials of adverse effects show only that there is a just significant increased tendency to non-right handedness in the offspring of women who had scans; the complexity of the study makes the observation difficult to interpret. Nevertheless continual vigilance is necessary particularly in areas of concern such as the use of pulsed Doppler in the first trimester. "
Obstetric Ultrasound - The Safety References (essentially the same page as above)
Ultrasound: Weighing the Propaganda Against the Facts by Beverley Lawrence Beech - "Obstetricians in Michigan (Lorenz et al., 1990) studied fifty-seven women who were at risk of giving birth prematurely. Half were given a weekly ultrasound examination; the rest had pelvic examinations. Preterm labour was more than doubled in the ultrasound group–52 percent–compared with 25 percent in the controls. Although the numbers were small the difference was unlikely to have emerged by chance."
Ultrasound: More Harm than Good? by Marsden Wagner (this is a good site to look at benefits vs risks, including having scans for "first pictures")
http://text.nlm.nih.gov/nih/cdc/www/41.htmlhttp://text.nlm.nih.gov/nih/cdc/www/41txt.html#Head3
Excerpt from the National Institutes of Health Consensus Development Conference Statement -- [February 6-8, 1984] - "For all practical purposes, fetal dose cannot be quantitated precisely. For this reason, there are no data on the dose to either the mother or the fetus in the clinical setting."
"A number of biological effects have been observed following ultrasound exposure in various experimental systems. These include reduction in immune response, change in sister chromatid exchange frequencies, cell death, change in cell membrane functions, degradation of macromolecules, free radical formation, and reduced cell reproductive potential. It should be noted that (a) some of the studies employed energy levels greater than would be expected to exist in clinical use; (b) in vitro exposure conditions to ultrasound used in many of the experiments are hard to place in perspective for risk assessment; (c) some of the observations, for example, sister chromatid exchange frequency changes and induction of chromosomal abnormalities, have not been reproducible, tending to refute the original findings. Nevertheless, some of the reported effects cannot be ignored or overlooked and deserve further study as outlined in our answer to Question 5. The existence of these studies is one of the factors that contributed to our decision that routine ultrasound screening cannot be recommended at this time." http://text.nlm.nih.gov/nih/cdc/www/41txt.html#Head6 "Ultrasound examinations performed solely to satisfy the family's desire to know the fetal sex, to view the fetus, or to obtain a picture of the fetus should be discouraged. In addition, visualization of the fetus solely for educational or commercial demonstrations without medical benefit to the patient should not be performed."
March of Dimes says:
"Ultrasound is considered safe for mother and baby."
(editorial) Considered safe. That doesn't mean they _are_
safe. Xrays were "considered safe" for years until problems
with over-exposure started to come into public scrutiny. We
know that listening to a rock concert can cause permanent damage
to one's hearing. Ultrasounds are high frequency sound
waves. By the time they get to the baby - what is he
hearing? There are frequencies that can kill. There are
other frequencies that can do other types of damage.
Are we sure ultrasounds are safe?(end editorial)
Ultrasound - weighing the propaganda against the facts "Low detection rates (either from poor equipment or unskilled operators) means all the babies get the ultrasound dose but few of them get the 'benefits' of accurate diagnosis. The skill of the operators will vary (everybody has to learn sometime) but even with the best machines and the best operators misdiagnoses occur."
Ultrasound Studies "The study of Liebeskind et al in 1979 also indicated that exposure to diagnostic levels of ultrasound insonation for 30 minutes caused increase in SCEs in human lymphocytes and in a human lymphoblast line."
Birth Trauma (this site should be added to your "birth trauma" section - risks and benefits) "The routine use of ultrasound has caused some concern expressed in the research. In a NEJM paper, the use of ultrasound did not change the perinatal outcome in 15,151 low©risk pregnancies. Ultrasound has been found to be associated with delayed speech and dyslexia in children."
ULTRASOUND IN OBSTETRICS: A QUESTION OF SAFETY "Millions of women and their unborn children are being exposed to diagnostic ultrasound during pregnancy and childbirth without the women being advised prior to exposure that there has been no well-controlled scientific investigation carried out to study the delayed, long-term effects of ultrasound on human development. Ova, embryos and fetuses are often exposed to prolonged sonography because the physician or technician lacks sufficient expertise to evaluate what he or she is seeing."
Risks of Ultrasound Screening "I do not agree with the statement that "a lot of embryos have been exposed to ultrasound over the last 25 years with no documented ill effects." Lieberskind's research indicated changes in cell structure that persisted over 10 generations and although researchers attempted to rubbish the research it was repeated by other researchers, and now we have research from Ireland that also shows affected cells." "...there is no evidence that infant outcomes have been improved by routine ultrasound examinations. Researchers have enthusiastically focused on what ultrasound could find but have paid little or no attention to the potential adverse long-term effects. As a result, despite ultrasound being enthusiastically used over the last 30 years, there is no good research that addresses the anxieties that ultrasound may be responsible for dyslexia, learning difficulties and behavioural problems."
Ultrasound Scans May Harm Unborn Babies "It would certainly seem prudent to avoid all routine absolutely unnecessary ultrasound scans for fetal observation. There appears to be more than enough evidence to warrant this recommendation. Pregnancy complications are another issue and one would have to weigh all the factors individually when attempting to determine the benefit/risk ratio."
Ultrasound Safe? "Ultrasound waves are known to affect living tissues in at least two ways. First, the sonar beam heats the highlighted area by about 2°F. This is presumed to be insignificant, based on whole-body heating in pregnancy, which seems to be safe up to 5°F. The second effect is cavitation, where the small pockets of gas that exist within mammalian tissue vibrate and then collapse. "
FETAL ULTRASOUND Ultrasound examination of the fetus may not be entirely harmless, reports Dr. Doreen Liebeskind at the Albert Einstein College of Medicine. Human lymphocytes and a continuously growing lymphoblast line exposed to diagnostic levels of ultrasound demonstrated a significant increase in the number of sister chromatid exchanges. Investigators believe that these exchanges indicated damage to chromosomes. (Family Practice News, April 1, 1980, p. 17) also (for your breast feeding page)
BREAST-FED
BABIES/DOCTOR VISITS Breast-fed babies visit the doctor less
often during the first six months than do bottle-fed infants,
according to Dr. Randolph Paine, a University of Iowa physician.
By six months of age, the breast- fed infants in his study had
averaged 1.65 visits to the doctor while bottle-fed infants
averaged 2.8. Over 75% of the breast-fed infants in the study had
never visited the doctor, other than for routine checkups or
accidents. Twelve percent had only one visit, and ten percent had
two to five visits by the age of one year. Only three percent of
the bottle-fed babies had no visits, and some of the remaining had
as many as sixteen visits. Infants who were exclusively breast-fed
for more than three months had significantly fewer visits during
the entire first year of life, and the longer the infant is
breast-fed and fewer the number of illness-related visits. Dr.
Paine states that there are five advantages to breast feeding: (1)
Human milk contains high levels of fatty acids which researchers
feel may be important in the growth of the baby's brain, (2)
Breast milk immunizes the baby until he can build his own
immunity, (3) Breast-fed babies have fewer allergies than do
bottle-fed infants, (4) Mother-infant bonding is strengthened
through breast feeding and (5) feeding the baby is much more
convenient and less expensive. (American Family Physician 21:210,
January 1980, p. 210)
Practical
Guidelines
for
Antepartum Fetal Surveillance from the AAFP - describes
fetal movement counts, nonstress test, contraction stress test,
biophysical profile, modified biophysical profile and
vibroacoustic stimulation.
All "normal" fetuses "breathe". Or at least they exhibit motions of the thorax, diaphragm, and abdomen that appear like breathing motions, thus the name for them. Fluid is moving in and out of the lungs. This has been documented using Doppler sonography to measure and image the fluid motions (for color Doppler images of this, see Cartier MS, Fetal Doppler, in DuBose TJ (Editor); FETAL SONOGRAPHY, W. B. Saunders Co. 1996, pp. 301 & color plate 13-33). As far as what is actually happening, who knows? The current theory is that this is a maturing process for the lungs, and may have something to do with preparing them by moving the amniotic fluids in and out of the lungs along with the lecithin sphingomyelin.
I do know that it is a normal and expected process. However, I am
NOT familiar with the absence of "breathing motions" being normal
within 72 hours of delivery. Of course, most of my experience has
been in outpatient labs and I have not done too may sonograms
right before delivery.
A physiologist told me that the decrease in fetal breathing is a result of prostaglandin increase. Agree that there could be benefits. Hadn't thought about yours with reduction of fluid in the lungs. I went with the mec. aspiration.
Birth
Weight
for
Gestational
Age - Public Health Agency of Canada
The Gestation Network
aims to highlight the importance of an individual approach in the
assessment of fetal growth, based on maternal, fetal and pregnancy
characteristics. This site contains free software for
calculating
gestational age and customised
fetal growth limits and birthweight
centiles.
June 20, 1995 issue of The Wall Street Journal, "Doctors Who
Perform Fetal Sonograms Often Lack Sufficient Training and
Skill."
I am finding that I have some clients who are particularly anxious to have an ultrasound and others who would shun one unless circumstances were dire.
I tell clients that US appears to be a wonderful tool, and that, to date, we know of no short-term adverse effects related to its use. However, they need to know that we only order them for medical indications (and I list these if they are interested) , that their insurance will only pay if there is an indication. Many people are surprised to find out that we don't know if there are any long term consequences of this technology and that moreover, it can take many years to figure that out. I tell them that is because of this that I would rather stick to ordering US when the info gained is really important in clinical decision making. This is a sensitive issue in some ways for me because my backup physician recently got a US machine and will US just about any thing that moves, and I understand why but it makes me uneasy (not that I don't know that this behavior is pretty commonplace).
I also talk to couples about the other ways in which we can be
attuned to whether a pregnancy is going well, and emphasize that
no technology can guarantee a perfect outcome but that by being
responsible about self care, they play the primary role in
ensuring good health for their offspring.
U/s can rule out some placental defects, and show heartbeat, but Doppler can usually give a heart beat too. otherwise its just window dressing. this is the "speech" I use about u/s in general.
It is my understanding that the ultrasound waves used in a sonogram are pulsed where the ultrasound waves used in the Doppler are continuous. They have the potential of being more dangerous than a sonogram in this spectacle of unknowns for two reasons. If the most damage is done from long exposure, then a fetal monitor during labor has more potential for damage than the others, if damage is more likely during a certain stage of development then the doptone device is sure to hit it. And, though I can't remember reference to this, isn't it also possible that a continuous wave is more dangerous in itself?
It seems a contradiction to me to on the one hand recommend that
a client avoid a scan and on (or in) the other hand use a Doppler
at prenatals and during her birth. Ultimately, I assume, we all
will give the clients what they want if we can and unless we are
emphatically opposed but I hope they can make informed choices.
I agree with the above statement. However, the statements about
danger from ultrasound is exaggerated, for continuous wave Doptone
or pulsed sonography (imaging). The Doptone has been in very wide
use for decades with no problems found. How long do we have to go
through this before we acknowledge that sound waves at the levels
we are talking about just are not dangerous. Think about it, this
is ultrasound, therefore can not be heard by humans or any living
thing at these frequencies. However, what other high frequencies
are people around every day that we can't hear? How about high
frequency sounds from auto engines, jet engines, electric motors
and house hold appliances? The major risk is during the
embryogenesis stages for heating. Blood flow and interstitial
fluid motions dissipate the heat faster than it can accumulate. I
am sure a mother will raise her core temperature more by lying in
the sun than from any medical use of ultrasound.
Recommendation
against
routine
third-trimester
ultrasound examination of the fetus - prepared for the U.S.
Preventive Services Task Force
Mother Rails Against Ultrasound
Doptones use continuous ultrasound waves. Those of you who want to avoid ultrasound should avoid doptones, ultrasound scans, and external electronic fetal monitoring. Ultrasound waves do cause changes at the cellular level, including causing them to heat up, grow in weird ways - loss of contact inhibition (contact inhibition is what keeps cells from growing into each other in normal circumstances) - cells that become cancerous lose their contact inhibition.
Ultrasound does cause cell changes, and should be used only when
medically necessary or medically indicated. Or in labor, perhaps
when it is easier to check the heartbeat quickly, if necessary.
The information about 1 min of Doppler = 35 min of ultrasound is in Anne Frye's Holistic Midwifery and her Understanding Diagnostic Tests in the Childbearing Year. This is because the waves used in a Doppler are continuous while the ones from an imaging ultrasound are pulsed. Electronic fetal monitors are continuous Doppler. Occasionally there is a place for this technology but all the time ? --- NO !!
This is from A Guide to Effective Care in Pregnancy and Childbirth by Enkin, Keirse and Chalmers. For those that don't know, this book is a guide to a huge two-volume book in which the studies done on most everything done in obstetrics have been evaluated and conclusions drawn. This work is also the basis for The Oxford Database of Perinatal Trials.
I quote " There has been surprisingly little well-organized research to evaluate possible adverse effects of ultrasound exposure on human fetuses. " ....... " The place of ultrasound for specific indications in pregnancy has been clearly established. The place, if any, for routine ultrasound has not as yet been determined. In view of the fact that its safety has not been convincingly established, such routine use should for the present be considered experimental, and should not be implemented outside of the context of randomized controlled trials. "
You might also be interested to know that what you hear with a
Doppler is not actually the babies heartbeat. It is a man made
sound. A transducer interprets the reflected ultrasound waves and
turns them into an audible sound.
http://www.changesurfer.com/Hlth/EFM.html
Efficacy and safety of intrapartum electronic fetal monitoring: an
update.
http://www.childbirth.org/articles/efmref.html
Fetal Monitoring FAQ
http://www.childbirth.org/articles/efmfaq.html
Routine Electronic Monitoring Of Fetuses Is
http://www.childbirth.org/articles/efm1.html
On the safety of prenatal ultrasound
http://www.alternamoms.com/ultrasound.html
Risks of Ultrasound Screening
http://www.midwiferytoday.com/enews/enews1n31.htm
Shadow of a Doubt
safety of ultrasound scans
http://www.newscientist.com/ns/19990612/newstory12.html
Ultrasound
Report on US from Internat'l. Chiropractic Pediatric Assoc.
http://www.compleatmother.com/ultrasound_danger.htm
Ultrasound: Weighing the Propaganda Against the Facts
http://www.midwiferytoday.com/articles/ultrasound.htm
What happens when you alter settings on your diagnostic ultrasound
machine?
Safety considerations for ultrasound
>http://www.efsumb.org/tutpap1.htm
Ultrasound vs. Fundal Measurement to Detect IUGR: Lancet 342
(1993) pp 887-891) - gave one group of women several scans, and
the other one scan. The only difference was that the intensively
scanned group had a higher IUGR rate.
Ultrasound
may change baby's cell growth [Brennan, Dublin, New
Scientist, 1999]
Effects
of
frequent
ultrasound
during pregnancy: a randomised controlled trial.
Newnham JP, Evans SF, Michael CA, Stanley FJ, Landau LI
Lancet 1993 Oct 9;342(8876):887-91
A study of over 1400 women in Perth, Western Australia compared pregnant mothers who had ultrasound only once during gestation with mothers who had five monthly ultrasounds from 18 weeks to 38 weeks. They found significantly higher intrauterine growth restriction in the intensive ultrasound group. These mothers gave birth to lower weight babies.The researchers concluded that prenatal ultrasound imaging and Doppler flow exams should be restricted to clinically necessary situations. This recommendation comes at a time when ultrasound during prenatal visits has become increasingly popular and serves as a kind of entertainment feature of office check-up visits.
OB/GYN News July 15, 1993, Volume 28 #14, which says basically
that ultrasound screening of low-risk women provides no clinical
benefits for mother or baby, and did not change the rate of
adverse perinatal outcomes. It discusses placenta previa, but
nothing about growth retardation. In another article (from the
Journal of Nurse-Midwifery Vol 29 No. 4 from July/August 1994)
"Preliminary data from the United Kingdon suggests a higher
incidence of leukemia is found in children exposed to diagnostic
ultrasound. This article also mentions that one of the indicated
uses is for establishing gestational age when there is a 2-3 week
discrepancy in dates, but also does not specifically discuss
growth retardation, however, this second article has a list of 16
references at the end.
More Discussion Regarding Link Between
Ultrasound and IUGR
What studies of DNA changes?
I've never heard of one!
Where are they!?
I'm serious... I REALLY WANT TO KNOW!
If they are out there, then we NEED to see them.
Does anyone have anything concrete anywhere?!
Hopefully someone will post NEW stuff, but a couple of old things things came to hand, from the '70s & early '80s when I was semi- organized & actually got some things into the file:
A letter to the editor in Birth & the Family Journal (now
called Birth) V4:3 refers to these studies with conflicting
results re chromosome damage (other studies are cited on other
aspects of u/s):
Galperin-Lemaitre & Kirsch-Volders
Ultrasound & Mammalian DNA
Lancet 2:662, 4Oct75
Fischman
Ultrasound & Marrow-Cell Chromosomes
Lancet 2:920, 20 Oct73
Macintosh & Davey
Chromosome Aberrations Induced by Ultrasonic Fetal Pulse Detector
Brit Med J 4:92, 1970
Mermut, et al.
The Effects of Ultrasound on Human Chromosomes In-Vitro
Obstet Gynec 41:4, 1973
Fetal Effects of Ultrasound: A Growing Controversy, D. Haire; J
Nurse-
Midwifery V29N4 July/Aug84
summarizes the (then) unknowns & areas of concern, gives
references, and includes a sample/proposed informed consent form
for u/s exposure. (!!)
Research in Ultrasound Bioeffects: A Public Health View, M E
Stratmeyer;
Birth Fam J 7:2 Summer 80
reviews human & lab studies, gives references to the studies.
The People's Doctor V7N11 is on u/s, contains such tidbits as: "On February 13, 1979, the FDA sent a letter to all physicians notifying them of the biological effects in test animals exposed to ultrasound at levels representative of ultrasound's current diagnostic use." "...Dr Liebeskind [asst. prof. of radiology, Albert Einstein College of Medicine] observed changes in cell appearance, motility, and DNA synthesis that were passed on in succeeding cell generations..." (I think it's her work that I saw a video or movie about, years ago; there's a reference to her on a tv news show in at least one of the other papers listed here.) Also mentioned in this issue are the Oxford Survey of Childhood Cancers (Britain) and the WHO 1982 publication on ultrasound.
Birth 13:1 accidentally published some uncorrected proofs of articles on u/s, the corrected ones were subsequently published as a 'special supplement' in Dec '86.
ICEA has published position papers on diagnostic u/s & EFM
which are well referenced & might be of interest; does anyone
have recent versions of these?
Ultra-Screen®
from
NTD
Laboratories is a First-trimester prenatal screening
protocol designed to provide patient specific risk for Down
Syndrome, trisomy 18 and other chromosomal abnormalities.
Ultra-Screen® combines ultrasound measurement of the fluid
accumulation behind the neck of the fetus (nuchal translucency)
with maternal serum markers and is the earliest and most effective
Down Syndrome screen available.
Half
of Chromosomal Defects Seen With Nuchal Translucency Are Not
Trisomy 21
A lady colleague of mine has heard of a procedure, to determine the health of an unborn child early in the pregnancy, could anyone explain the procedure in reasonable technical detail, how it works its advantages, disadvantage and exactly what can be determined.
Using ultrasound at ~10 weeks it's possible to measure the thickness of the soft tissue at the back of the neck/base of skull. There are data to suggest that ( subject to correction for gestational age and maternal age ) can be used to predict the risk of Down's syndrome and other trisomies in the fetus. This is achieved with detection rates comparable to maternal serum screening and has the advantage of allowing earlier suspicion and thereby earlier definitive testing to give reassurance or allow option of termination of pregnancy.
There are also other data to suggest that with extreme nuchal thicknesses, even with normal chromosomes the fetus may have other life- threatening anomalies or be at risk of second trimester loss.
Other workers have cast doubts on the effectiveness and value of
this method as a population based screening tool. More work is in
progress, as is work attempting to combine nuchal scanning with (
new ) maternal serum markers.
These days a dilated ureter is noten on the chart only when it is
VERY dilated. And it isn't seen as cause for concern unless there
are other problems found.
In a day and age where 'global' fees for prenatal care don't even
begin to cover the costs of doing business (like malpractice
insurance), this finding is yet another portal of opportunity to
'medicalize' pregnancy and therefore increase reimbursements for
what is an otherwise normal developmental finding. It is also a
very effective tool for creating dependency on the system by
sowing seeds of doubt and then reinforcing them with anxiety in
the form of serial visits/testing. I think this particular one is
getting worn out as people get wise to it....... That said, my
parameters in absence of any suspicion for abnl chromes would
be 4mm to 7 mm watch, >7mm (as in 'very'?) refer MFM for
eval/man.
I think it usually means the baby needs to urinate!
excerpts:
5% of fetuses lack umbilical vascular coilingRecommendations from the article:...among neonates without umbilical coiling, one team noted a 10% stillbirth rate. As such, the straight umbilical cord may present a risk for intrauterine death that exceeds that with maternal diabetes or hypertensive disease.
Other reports have have documented significantly increased rates of intrapartum FHR decelerations, operative interventions for fetal distress, and meconium staining. Some have noted higher rates of fetal growth retardation, oligohydramnios, fetal anomalies, low APGAR scores, low umbilical arterial pH values, neonatal intensive care unit admissions, and preterm deliveries.
See also: Nuchal Cord -
Somersault Maneuver
Prenatal
ultrasonographic
diagnosis
of
nuchal cord(s): disregard, inform, monitor or intervene?
Sherer DM, Manning FA
Ultrasound Obstet Gynecol 1999 Jul;14(1):1-8
Nuchal
cords:
timing
of
prenatal diagnosis and duration.
Collins JH, Collins CL, Weckwerth SR, De Angelis L
Am J Obstet Gynecol 1995 Sep;173(3 Pt 1):768
Nuchal cords can be diagnosed prenatally with ultrasonographic imaging. A prospective study determined the timing of nuchal cord formation and, in some cases, resolution before delivery.
What do you do when you find a nuchal cord X's 2 in a normal
pregnancy at 38 weeks gestation ???
I try to decide, from the u/s, whether it seems to be a tight
wrap or just a loose one. If it's loose, I generally don't
actually DO anything but make a mental note and watch for it at
delivery. If it's noticeably tight, I tell the parents, get the
mother to do kick counts and stuff, watch the AF volume, and be
very nervous... If I even think about it, I do NSTs, but they are
almost bound to show small variables, at least, from the
beginning. And finally, I don't let the lady labor at home. At the
first inkling of contractions, she goes in to be monitored.
Excellent plan. I would do pretty much the same thing.
How do you tell from ultrasound whether a nuchal cord is tight or
not?
Interesting question... The best answer I can give you is, how do
you tell (without touching) whether a nuchal cord AT DELIVERY is
tight or not? I just look... it seems fairly obvious to me when a
cord is tight or loose and flapping in the breeze. Ultrasounds are
VERY good these days, and I haven't really given that question
much thought.
Color Doppler should provide some information neh?
Not to belabor this point but i do recall speaking with Dick
Berkowitz about nuchal cords on ultrasound and he was most
emphatic in his suggestion that this NOT be reported. perhaps this
finding in a woman who offers that her fetus' movements have
significantly decreased might have a different import; but barring
this, we create the great potential to create more problems than
we avoid.
Dr Hon had a very good maneuver he used. Press on the fundus and
watch response of the FHR.
Not an issue. Cords are common -- what, maybe 20% of kids at birth? (and I think it's a great reason to avoid AROM). The kiddo is really unlikely to get the cord tight enough to cause problems in pregnancy -.. I would not be any more -- or any less -- watchful at this birth than at any other births. We've all seen TONS of cords round necks -- once twice three times, more -- only on the most rare occasion is a cord ever an issue. Heck, half the time we hear the rare FHTs which are associated with cord pressure, the cord isn't around the neck anyway -- it's wrapped elsewhere.
A baby is designed to have a cord long enough to allow it
to get born without causing difficulties. The uterus itself
descends during second stage as the baby travels through the
birth canal, giving an extra six inches or so of
slack. cause ANY
problem in labor. For a cord to cause serious problems with fetal
circulation it has to get really tight -- and if it's THAT
tight it will generally interfere with position and/or
descent. The only cord around the neck which I would worry
about is the one on a transverse or breech baby --- if the kid has
enough cord slack to be a normal vertex, then I wouldn't
worry at all. I think it proves the cord will not become a
problem.
I had a VBAC client whose ultrasound tech suspected a triple
wrapped cord. Baby was born yesterday at home - heart tones
perfect throughout labor, head born, one loose cord wrap and easy
birth. 10-10 apgars. I stressed when told about the
"cord wraps" and what to tell the Mom. As it wasn't possible
to say it was definite, we told her there appeared to be a cord
wrapped around the baby's neck, maybe more than one time and we'd
watch for problems relating to it. She completely let it go
and didn't worry.
I consider cord wraps a variation of normal, as long as the baby
is not in distress, neither am I. Fortunately, we have a
supportive hospital to transport to which is five minutes away -
so I am comfortable with this.
Obstetrical
Sonography: The Best Way to Terrify a Pregnant Woman by Roy
A. Filly, M.D.- an excllent discussion of abnormalities which are
not really abnormalities: choroid plexus cysts (3-31), echogenic
intracardiac foci (32-36), mild pyelectasis (37-41), and echogenic
bowel (42-45) .
FAQ:
Choroid Plexus Cysts from ucsfhealth.org. It seems to
have written before cell-free DNA testing was available to rule
out trisomies without risking a miscarriage from amnio.
Should
I
Be
Worried
About a Cyst in My Baby's Brain? (Cranial Ultrasound) -
don't worry about only one isolated choroid plexus cyst smaller
than 10 mm.
SEX, HEART RATE, and AGE by Terry J. DuBose, updated July 26, 2011
I do notice tachycardia in getting heart tones with a dopp very
early in pregnancies. Do you notice this? Or do you think this is
WNL for early development?
Fetal heart rate is higher in early pregnancy than in later
pregnancy. We can listen with a Doppler at 14 weeks but not likely
with a stethoscope till closer to 20 weeks. I think this is a
normal thing we should expect.
I have done a lot of research on the embryonic heart. Actually, it is quite interesting. It is partially correct that the EHR is higher early in pregnancy than later, however only partially correct. The EHR starts out as early as we can see it with sonography at about 78-85 B/M in the early 5th LMP week. It then accelerates in a linear fashion to approx. 165-190 B/M in one month (early 9th week). That is an acceleration rate of approximately 3.3 B/M per day, or 10 B/M increases every 3 days. Then abruptly at approximately 9.2 LMP weeks it begins a relatively quick deceleration until the about the 18th week when it starts to level out, but still a slow deceleration to about 144 B/M near term. In our population (3000+ cases), embryos (5 of 6) that fell below the acceleration curve by more than 7 days (EHR age - CRL age) ended in 1st trimester miscarriage. [Ed. CRL = crown-rump length]
I realize that you can't find the faint EHR as early as we can see it and measure it with M-mode, but it really is quite fascinating. The embryonic heart rate acceleration is very consistent with little beat-to-beat variability, unlike the variation we expect (is normal) during the 2nd & 3rd trimester. I published the first regression formula for predicting the embryonic age from the HR, which is valid before 9.2 LMP weeks:
Embryonic age in days after LMP = EHR(0.3)+6 Embryonic age in days after conception = EHR(0.3)-8
This is only valid during the first month of life, but is more
accurate than the gestational sac diameter, but not quite as
accurate as the Crown-Rump Length. For more information including
large population graphs, more regressions, and discussion of the
heart rate throughout gestation see: DuBose TJ; FETAL SONOGRAPHY;
W. B. Saunders Co., 1996; Chapter 12, Heart Rate.
For those women who have discovered catastrophic problems with their pregnancies and have decided to terminate the pregnancy rather than risk death due their own medical condition or otherwise tragic result in carrying a pregnancy to term . . . there is some good information at the web pages of the Boulder Abortion Clinic. "Our purpose is to provide the safest possible abortion care and termination of pregnancies for fetal anomalies or medical indications. We provide this care for women in a confidential, humane, and dignified outpatient setting giving the maximum emotional and social support."