"Admission cardiotocography is widely used to identify pregnancies that might benefit from continuous fetal monitoring in labour. Lawrence Impey and colleagues did a randomised controlled trial to compare the effectiveness of this procedure with intermittent auscultation and continuous cardiotocography only if clinically indicated. They found that routine use of cardiotocography for 20 min on admission to the delivery ward did not improve neonatal outcome. In a Commentary, Stephen Thacker and Donna Stroup comment that use of this procedure "should be discouraged until better evidence . . . is available".
Randomised
controlled
trial of cardiotocography versus Doppler auscultation of fetal
heart at admission in labour in low risk obstetric population.
[Full
text]
Mires G, Williams F, Howie P
BMJ 2001 Jun 16;322(7300):1457-62
Conclusions: Compared with Doppler auscultation of the fetal heart, admission cardiotocography does not benefit neonatal outcome in low risk women. Its use results in increased obstetric intervention, including operative delivery.
Electronic
fetal monitoring - Is not necessary for low risk labours
Editorial by Goddard
BMJ 2001;322:1436-1437 ( 16 June ) (Editorials)
The chief recommendation is that intermittent auscultation is the most appropriate method of fetal monitoring for women in labour who are low risk. This allows the best compromise between assuring fetal safety and allowing the woman mobility and independence during labour. For auscultation to be successful it needs to be frequent, especially in the second stage of labour, and therefore requires one to one care of the woman. Unfortunately this is an ideal which may be impossible in hard pressed labour wards, where midwives are often in short supply. Ironically, there is good evidence that one to one care alone has a powerful effect on the labouring woman, reducing intervention.8 The cardiotocograph can become a surrogate for this best quality care and has a major impact on the caesarean section rate.
Neonatal
Mortality
Risk Drops With Fetal Heart Rate Monitoring [2011]
The experts still don't agree on whether this study should change
guidelines for monitoring.
NICE
Guidelines - Full clinical guideline on the use of
electronic fetal monitoring (published by the Royal College of
Obstetricians and Gynaecologists)
Interpretation
of
the Electronic Fetal Heart Rate During Labor by AMIR SWEHA,
M.D., and TREVOR W. HACKER, M.D. - Excellent tutorial from the
AAFP.
Intrauterine
Asphyxia:
Clinical Implications for Providers of Intrapartum Care
[1/3/06]
Michelle Murray, PhD, RNC is an expert on fetal monitoring and
offers a variety of learning
and practice books and aids.
Listening
to
the Fetal Heart: A Brief History
Effect
of
fetal sex on labour and delivery: retrospective review
BMJ 2003;326:137 ( 18 January, 2003 )
"Male infants are just as likely to be born healthy as females,
but expectant mothers of female infants tended to have fewer
complications during childbirth than those delivering male
infants. . . . Male infants tend to be heavier and have
larger heads, but that would not explain all of the
differences seen, Dr. Eogan noted. "Male infants are more
likely to become distressed by the process of labor, it may
just be that male infants are more vulnerable to these stresses."
Fetal Heart Rate Tutorial/Review
This great website is from the United Kingdom and is a
hospital-based site the has created a tutorial for physicians and
midwives for the self-study of EFM tracing and appropriate
treatment responses. It includes a free down load for
"test-driving" their program which is sold for 30 pounds.
Personally, i don't expect to buy the whole program but it would
be appropriate for teaching institutions or individuals that are
teaching or a midwifery self-study group that was willing to share
the expense. And i learned some useful little tidbits just from
the free part.
Monitoring the
heartbeat - Excellent Patient Education from Kent Midwifery
Practice in the UK (Kay Hardie and Virginia Howes)
Maternal Heart Rate Mistaken for Fetal
Heart Rate
But the birth went very smoothly up to the last 20 minutes when the baby had what at first seemed like head compression decels - down to 72 during contraction, back up to 132 immediately afterwards (i do FHTs in 5-second increments x 60 seconds after a UCtx to monitor for normal variability / reassuring patterns.) Then the baby started to have variables -- down to 60bpm for 45-90 seconds between UCtx, then back up. Had her not push for a couple of UCtxs, baby was a lot happier -- was sure it was a nuchal cord being pulled tight and having vasospasms and then adjusting. Finally decided the baby just needed to be born (as FHTs continued to yo-yo around) and so had her push on the Dutch midwives' birth stool and the baby somersaulted through a several loops of loose cord. Great apgars, FHT 132 at one minute.
Then 3 hrs later i did the newborn exam and could hear a real pronounced inspirational arrhythmia when the baby took a deep breath or yawned -- HR went from 130 to 0 for 2 seconds, then started up ever so slowly for another 10-15 seconds then back up to baseline. I called my MD-midwife friend (who had no suggestions) and so we started to hunt for a pediatrician but with no luck (it was saturday). At 5 hours of age, the baby was asleep and so i listened to see what the rate was when she wasn't crying or moving about. Unfortunately, it was between 60 and 70 and i didn't feel that we could delay medical investigation so we connected with a pediatrician and went to the ER. We were well-received (as paying customers with good insurance!) but the care was very dis-jointed -- they put her on the monitor, did blood sugar, EKG and pulsoxamentor (sp??). Also, only one nurse and the women pediatrician washed their hands before handling the baby. After 5 hours the baby was released untreated with a diagnosis of mild idiopathic bradycardia.
As for what i learned -- that vagal decels can be idiopathic (not
from cord or head compression) and show up both before AND after
the birth.
Lawrence
DeVoe,
M.D., explains the Stan System fetal monitoring system
Except that STAN is rearranging deck chairs on the Titanic. What
the fetal heart rate is doing in labor has little to do with
condition at birth, and condition at birth has little to do with
long-term problems. Therefore what the fetal heart rate is doing
in labor has pretty much no connection with long-term outcomes. As
I write in the chapter on EFM in the new edition of Ob Myths,
"Fortune tellers may hold workshops to teach tea leaf reading;
they may come to consensus on what they believe certain patterns
portend; they may even develop programs to perform computerized
analyses of tea-leaf patterns, but they are still reading tea
leaves." [from Henci Goer, author of The Thinking Woman's
Guide to a Better Birth and Obstetric Myths Versus
Research Realities.]
Techniques Confirmed to Improve Fetal Oxygen Status During Labor By Anthony J. Brown, MD - June, 2005 [Medscape registration is free].
"NEW YORK (Reuters Health) Jun 03 - Researchers have shown that three intrauterine resuscitation techniques commonly used to improve fetal oxygen status during labor are indeed useful when the fetal heart rate (FHR) pattern is nonreassuring, according to a report in the June issue of Obstetrics & Gynecology.
These techniques are: giving the mother an IV fluid bolus of 1000
mL, placing her in a lateral position, and administering O2 at 10
L/min with a non-rebreather face mask. . . . "
Homebirth midwives might consider carrying terbutaline for emergency use during transport to the hospital for fetal distress. This would be especially useful for
The appropriate dosage for intrapartum use is 0.25 mg subcutaneous terbutaline.
This would add an extra measure of safety for:
Nuchal cord: During the rare times when cord around the neck becomes tight enough that it reduces the blood flow through the umbilical cord enough to affect fetal oxygenation, it is possible to push the baby up higher through the vagina. Administering terbutaline would reduce contractions that would push the baby lower and tighten the cord again.
VBAC: Catastrophic uterine rupture during a VBAC labor is very rare, but if you think there might be a problem and are heading to the hospital, it makes sense to stop the contractions. This will prevent the uterus from pushing the baby through the rupture into the maternal abdominal cavity, which can result in premature placental separation and thus severe fetal distress.
Uteroplacental insufficiency: Most women who plan homebirth are
at very low risk for uteroplacental insufficiency, but it can be
relieved by stopping the contractions while you get to the
hospital.
From the Cochrane Collaboration, Chapter 30 - Care of the fetus during labor:
"Intravenous betamimetics are a useful treatment for 'buying time' when persistent fetal heart-rate abnormalities indicate a need for elective delivery. In a randomized, controlled trial involving 20 labors characterized by both ominous fetal heart-rate changes and a low fetal scalp blood pH, 10 of the 11 treated with intravenous terbutaline showed improvement in the heart-rate pattern, compared with none in the control group. At birth, the babies were less likely to be acidotic and to have low Apgar scores. The results of this trial are supported by other less well-controlled studies. This short-term improvement could be very useful in situations where facilities for emergency cesarean section are not immediately available. The improvement in the trace pattern is sometimes sustained. In these circumstances, labor may be allowed to continue without urgent delivery."
Randomized
comparison of intravenous terbutaline vs nitroglycerin for acute
intrapartum fetal resuscitation.
Pullen KM, Riley ET, Waller SA, Taylor L, Caughey AB, Druzin ML,
El-Sayed YY.
Am J Obstet Gynecol. 2007 Oct;197(4):414.e1-6.
RESULTS: One hundred ten women had nonreassuring fetal heart rate tracings in labor; 57 women received terbutaline, and 53 women received nitroglycerin. Successful acute resuscitation rates were similar (terbutaline 71.9% and nitroglycerin 64.2%; P = .38). Terbutaline resulted in lower median contraction frequency per 10 minutes (2.9 [25-75 percentile, 1.7- 3.3] vs 4 [25-75 percentile, 2.5- 5]; P < .002) and reduced tachysystole (1.8% vs 18.9%; P = .003). Maternal mean arterial pressures decreased with nitroglycerin (81-76 mm Hg; P = .02), but not terbutaline (82-81 mm Hg; P = .73).
CONCLUSION: Although terbutaline provided more effective
tocolysis with less impact on maternal blood pressure, no
difference was noted between nitroglycerin and terbutaline in
successful acute intrapartum fetal resuscitation.
Acute
tocolysis for suspected intrapartum fetal distress: maternal
effects of terbutaline versus magnesium sulfate.
Magann EF, Norman PF, Bass JD, Chauhan SP, Martin JN Jr, Morrison
JC.
Int J Obstet Anesth. 1995 Jul;4(3):140-4.
This study was undertaken to determine the maternal hemodynamic impact of terbutaline versus magnesium sulfate in the acute treatment of fetal distress prior to cesarean delivery. Forty-six women were prospectively randomized to receive 0.25 mg subcutaneous terbutaline or 4.0 g intravenous magnesium sulfate for in utero fetal resuscitation before cesarean delivery. There were no significant differences between groups in baseline mean arterial pressure, arterial pressure before and after induction of anesthesia, maternal heart rate, maternal oxygen saturation, estimated blood loss, and pre- and postoperative hematocrits. Magnesium sulfate-treated women received significantly more intraoperative intravenous fluids (2365 +/- 877 ml) than the terbutaline group (1624 +/- 564 ml; P < 0.001). However, mean urine output was significantly greater in the terbutaline group (88 +/- 42 ml/h) than in those treated with magnesium sulfate (61 +/- 26 ml/h; P < 0.03). Terbutaline, the superior agent for acute tocolysis, is not associated with an increase in maternal cardiovascular side effects during anesthesia.
Other trials show that terbutaline is significantly more
effective than magnesium, and that it is as effective as
nitroglycerine, but with less impact on maternal blood pressure.
Auditory Evoked Response Test to Evaluate Fetal Health
Auditory
evoked
response of the human fetus: simplified methodology.
Luz NP
J Perinat Med 1991;19(3):177-183
A test was considered positive when sound stimulation evoked no
movements or only a slight, slow, not immediate movement was
observed by the mother or the professional applying the test. A
test was considered negative (fetus in good health) when a fetal
immediate sudden, strong, Moro like reaction was observed
clinically (startle reflex). This test produced a sensitivity of
57.35%, greater than any other observed in nonstress
cardiotocography.
Anyone in this group still using acoustic stimulators?
Yes.
Worked in an IHS hospital that did not have the "real thing." So
we used a pepsi can 1/4 filled with pinto beans and would shake it
vigorously over the moms tummy. Worked just great. Lots cheaper.
You can also put an electric toothbrush on the abdomen.
The toothbrush should work better. There is at least one study
showing that the "Vibro" part of the VAS (Vibro-Acoustic
Stimulator) is very important. If my memory serves me correctly,
it was by Tony Vintzileos.
Clark SL, Gimovsky ML, Miller FC : Fetal heart rate response to scalp blood sampling. Am J Obstet Gynecol 144:706, 1982
Clark SL, Gimovsky ML, Miller FC; The scalp stimulation test: a clinical alternative to fetal scalp blood sampling. Am J Obstet Gynecol 1984; 148:274
Read JA, Miller FC: Fetal heart rate acceleration in response to acoustic stimulation as a measure of fetal well-being. Am J Obstet Gynecol 1977 ; 129:512
Smith CV Ngyuen HN, Phelan JP, Paul RH Intrapartum assessment of
fetal well-being" A comparison of fetal acoustic stimulation with
acid base determinations"
Why
Are We Using Electronic Fetal Monitoring? - an editorial
from the American Academy of
Family Physicians
Discussion
on
ob-gyn-l regarding switching back to Intermittent Auscultation
as a way to reduce liability. This movement is advocated by
Herbert Sandmire and Robert DeMott from Green Bay, Wisconsin.
Victoria Midwives Protocol - Observations
in labour
Failure
to
Rescue as a Process Measure to Evaluate Fetal Safety During
Labor - Intrauterine resuscitation measures table
How do you monitor the baby during labor?
A (somewhat rancorous) discussion has started among the midwives at my birth center about what our protocols should be for monitoring. We use a Doppler, all of us do some version of 5-6 second counts for variability, we check every 15-30 minutes in first stage. That much we agree on.
Here are the disputes:
1. During second stage: Listen to the FH after EVERY push? Yes/No?yes--and I might fudge on this a little in a perfectly normal straightforward 2nd stage, where absolutely no sign of distress have been noted. But I listen VERY often, because things can change quickly, which might affect my management of the delivery.
2. During first stage: Listen through a contraction EVERY time you monitor? Or listen through the occasional contraction, but otherwise listen just after a contraction, or in between contractions, and monitor more frequently or during contractions only if some abnormal rhythm is detected?I occasionally listen through contractions, certainly not every time. I am on hyper-alert, however, if anything unusual is heard. Then I would be listening almost constantly until it resolved,. or we made some sort of change or decision.
I believe that the ACOG recommendation for 2nd stage is to listen every 15 minutes for low risk and every 5 minutes for high risk (which theoretically you wouldn't have in a Birth Center, right?)
In first stage we listen through a contraction and 30 seconds after once every 30 minutes (or 15 minutes if it's a higher risk situation, though we don't get many of those at our little Level 1 hospital either). I have done only in between contractions while mom is in the tub or shower, but I think you're really supposed to do it through. It's been easier lately since we got the new waterproof Doppler from Sonicaid. Not only do you not have to get mom out of the water to do it, but it's a lot better at picking up the rate on the little display than our old one was. The only thing lacking on it is a backlight for the display, so I have the support person hold a flashlight for me, as I don't want to turn a light on - the little nightlight in the tub room is not enough to see the numbers.
It seems logical that you should be able to listen right after a
contraction instead, as the kind of thing you are concerned about
(lates or baseline changes) should show up then, but the official
guideline-setters didn't see it that way, I guess. I don't know of
any research evidence that compares the two (during vs. after) for
being able to pick up problems. I think the guidelines were
probably arbitrarily chosen, without comparing to anything else.
But if our care ever comes under scrutiny, you can bet they'll be
looking at how it compares to the official viewpoint.
In my state we have protocols we have to follow for monitoring FHR. In latent labor q 2h; during active q 30min; during 2nd stage q 15min, or more often if any signs/symptoms of a problem. We are supposed to listen during a contraction and for 30 seconds afterward. I base my auscultation on how the baby has been doing and my instincts about it - I follow this schedule but will alter it if there are concerns. When I feel really good about a baby and a labor, sometimes I won't listen all the way through a contraction, but I will always try to listen from at least the middle to the end of one and for a little bit after the contraction is completely over. If the Mom is in the shower or asleep or something, occasionally I will go over my 30 mins during active labor - only if I feel really good about the labor/baby. (I do what you do with 5/6 sec counts for variability.) During 2nd stage I only listen about every 15 mins - again, unless concerned, and then YES, I listen after every contraction. When I start seeing the scalp tones, I have something else to go by as well.
When I first started apprenticing - we didn't have a Doppler and
we listened with a fetoscope - really hard to listen through a
ctx! We didn't have the state rules back then and we just kind of
based it on our own protocols/feelings/concerns - each birth was
different. I really like my Doppler because I think it is so much
easier on the Mom during labor not to have to make her lie in a
certain position so I could hear. I can now hear pretty
much in any position she chooses to take. I still try to keep up
my listening skills though and will often ask if I can use the
fetoscope to hear once or twice on each birth.
I have been taught that anything that has no decelerations (even
variables) remains low risk, variables or other decels turn it
into high risk. However I have been working in the bosom of the
medical model where everyone is treated as high risk until
proven otherwise!! They wouldn't know how to treat a mom like you
all do!
We listen approx q 5 min. If FHTs have remained stable, may go an occasional 10 minutes w/ longer 2nd stages. Any time there's rapid progress in descent or any other sudden change (as in mom's position), we listen also. I personally think q 15 is not often enough in some cases, and you never know which ones those will be. We have had instances of FHTs dropping to 30 - 50 w/o recovery after being >120 5 minutes earlier. Have then had moms just push in squat or McRoberts to get babies out ASAP. Would hate to have not listened for 10-15 minutes in those occasional situations! Anyone who has been on the list for awhile knows I am very patient with heads on the peri, have great stats for no tears. It is knowing how the baby is doing that helps with that patience.
active labor ~ q 15-30 minutes w/ consistent FHTs, or after position changes by the mom, usually in between or just after contrx is over, occ through contrx, occ count for 5 sec intervals.
More often monitoring if anything is variant of normal.
Our state law here in Florida in regards to monitoring is:
Second stage: After every contrx, or q 5 whichever is more often. First Stage: Listen through a contraction maybe q 1 hr, usually just after (since late decels are most ominous anyway). Q 30 in latent, early active, q 15 in late active.
Just our protocols, others probably do differently.
I just follow ACOG guidelines, but seem to check fht more often
the longer 2nd stage goes, or if the baby seems to be taking a
long time doing the birth dance. Had one ON THE PERINEUM with much
scalp showing even between contractions for 45 min the other day.
But scalp was pink and fht perfect so just sat by the hole...
until at the last couple pushes I changed from flexing the head to
flex and release, flex and release, sort of rocked the head out.
9#2 1/4 oz boy over intact. I couldn't believe this primigravida
with condyloma all over the anterior fourchette delivered with
nothing more than a few labial skid marks.
Second Stage: Usually after every other contraction.
First Stage: Listen through the occasional contraction, but
otherwise listen just after a contraction, or in between
contractions, and monitor more frequently or during contractions
only if some abnormal rhythm is detected?
First Stage: We are presently formulating midwifery protocols for
IH births and we have hit upon monitoring through (i.e. during and
1 minute before and after) 3 contractions every 30 minutes, or
another suggestion is every 60 minutes- I guess we will try to get
the latter approved because we can always increase per need.
My question is... have you seen much in the way of low baseline,
and what are the common or otherwise implications of such? Tell
me/us your story please.
In my experience, low baseline with good variability, accels, and
other signs of well being is usually no big deal, possibly a large
baby (theory being that larger organisms have slower HRs, look at
hummingbirds compared to elephants) but I think that low BL with
any other factor would make me a little more nervous.
Have watched three or four baselines in the 100's in my fifteen years. No problem with the babies. I would have been reassured by the progressively lower baseline in pregnancy. This baby was just developing into a low baseline baby.
Variables in the 60's would not bother me, with variability and a quick return to baseline during pushing. Course, since I'm in the hospital already, my comfort level would probably be a little different than yours.
Particulate meconium is a problem for me. We have been flushing thick mec during labor with amnioinfusion. It's possible that the baby can suck a glob of the stuff into its trachea before the birth and place of birth would make no difference. But, I would want to share the responsibility of a good tracheal look and suctioning with people who have more experience.
We all have to work within our comfort level.
I have seen low baselines associated with persistent posterior
position. The explanation is that the position leads to more vagal
stimulation and lowers the baseline. I have sat anxiously staring
at a monitor with an otherwise normal looking strip, but the
baseline is between 110-120 or even 100-110 or in one memorable
case dipped into the nineties quite often. The bottom line on
monitoring seems to be (after all these years) that it is
variability that matters. If you have normal variability, you have
a normal baby with good reserve. You can't have a heart-rate of
sixty and still have variability. If you have "tachycardia" and no
fever you will probably still have variability, but if the mom
and/or baby are really sick you will have a flat high heartrate.
When I was in school, I remember reading an article on fetal heartrate monitoring and one of the comments about bradycardia was that the rate itself was less important than "the company it keeps", meaning, of course, that we always have to look at the larger picture.
I think that is important that we practice within our comfort
levels. Even if this birth might have been fine at home, you had
no way of firmly predicting that, Carol. Don't beat yourself up
for being cautious. After all, if you were not cautious, and you
had experienced an adverse outcome, it is very possible that some
of the same people who are saying you would have been fine not to
transport under the circumstances, might have been saying, "you
should have known".
Regarding your low heart tones I have several stories. I've seen
GI defects cause both tachy and bradycardia. One with
tracheo-esophogeal atresia had a persistently high baseline:
160's; and another with bilateral cleft lip and palate had low
heart tones: 100-110. The first was a home birth the second a
hospital birth. Which one do you think got sectioned?? The heart
rate is regulated by both the sympathetic and parasympathetic
nervous system; and the baby who couldn't swallow probably wasn't
getting all the usual slow down messages, and vice versa. I've
also had several babes who persistently skipped a lot of beats.
Supposedly PVC's. One did it consistently every third or forth
beat, for months. That's a lot. He was a 10 pounder with lots of
meconium, but as soon as he was born it stopped. I think that the
foramen ovale was causing an impulse block and that as soon as he
was born and the foramen closed that was the end of that. But it
sure had all the characteristics of PVC's. Which too are basically
benign. It was probably cautious to transport in view of the
meconium. I probably would have based my transport decision on how
I thought the parents would deal with the potential postpartum
drama. The TEA babe was an obvious immediate transport and
surgery... and we birthed the next brother at home, with much less
drama. If the baseline is low and all else is fine, don't sweat
it.
What do you do about tight cords and long decels?
I've found that it really helps to relieve the tension on the
cord in between contractions. Let the head come down with
the contraction and encourage it to retreat completely in between,
even pushing them back up to relieve the tension. This will
give baby much better reserves for the time when you can no longer
relieve the tension. I find I can push them back in almost
up until a full crown.
Is it true that babies' heart rates can and often do drop and
fluctuate dramatically during second stage?
The most common change in fetal heart tones in second stage is a pattern called an "early decel", where decel is short for deceleration. This is a normal physiological response to pressure on the baby's head, as when the head meets the resistance of the pelvic floor muscles or the pelvis itself, often the ischial spines.
An early decel is a drop in FHR (fetal heart rate) that mirrors the contraction, i.e. as the contraction strength builds, the FHR drops, until the contraction strength reaches its peak at about when the FHR reaches its lowest point, and then the FHR goes back up as the pressure of the contraction decreases. FHR can reasonably go down to 90, some would say 60, but not for too many contractions in a row.
The key point is that if the baby's heart rate goes right back to normal as soon as the contraction ends, this is a sign that the baby is not in any kind of distress. If the baby's recovery lags 15 seconds or so beyond the end of the contraction, this is a concern. This means that the contractions themselves are a source of stress to the baby - for some reason, oxygen flow is significantly diminished during the contraction - as when pitocin causes extra strong contractions that squeeze the placenta and keep blood from flowing through to the baby. So it takes a while for the oxygen flow to be restored after the contraction.
If the baby's heart rate remains normal until the peak of the contraction and then dips and then doesn't really recover until about 30 seconds or more after the contraction, this is a "late decel" and is indicative of fetal distress.
In any case, there's an easy test called scalp stimulation to assess the baby's well being. Basically, you rub the baby's scalp with your finger; if you see a rise in FHR of 15 points for at least 15 seconds, the baby is not in distress.
It's a lovely, simple procedure and beats the heck out of fetal
scalp sampling (i.e. taking a blood sample from the baby's scalp).
Is there anyone out there who would be uncomfortable w/ FHs in
the 90s for 10-15 minutes immediately before birth?
My understanding is that as long as the baby has had FHR WNL with
good variability through labor, it can tolerate 10-15 minutes of
terminal bradycardia.
I remember lots of heroics in hospital in second stage that were
iatrogenic; i.e. unphysiologic births, mother semi-supine,
prolonged breath-holding and then lots of FH dips with gradually
slowing recovery - hardly surprising. Lots of babies delivered
instrumentally that were fine. There seems to be a consensus that
our understanding of the range of normal fetal heart rate in
second stage is minimal... I remember reading some research on it
a good few years ago that said that a moderate second stage
bradycardia was 'normal' (but of course all research done in a
hospital setting with unphysiological birth), and that
babies could happily withstand a fair time of it.... but of course
nobody knows how long an individual baby (with its own individual
resources) can happily take. How that applies to a woman
giving birth physiologically is hard to say; as she probably will
be moving around, not doing all that prolonged pushing, so should
experience less bradycardias per se - which is certainly my
clinical experience.
Back in the time when I witnessed a lot of CTG tracings it seemed often a bradycardia was associated around start of second stage and/or head descent. Some of the senior midwives and experienced doctors got fed up with being called into labour suite room just in time to see foetal heart rate recover. They starting setting criteria that the first brady would have to be lower than 90-100bpm and be lasting up to 4 minutes before they should be called. However, any further bradys or frequent decelerations or loss of contact in monitor, out would easily come the artificial rupture of membranes, the barracking or the forceps or the ventouse or c/s. As I gained experience and qualified I found that in most situations changing positions made all the difference and resulted in normal births (This really was only 10 years ago in maternity units when being on all fours was still considered highly radical as a position to give birth in.
When I have listened in (intermittent auscultation) at the many home births I have attended so far I have to declare that I've picked up a bradycardia once(about 90bpm and a few minutes long, G6P5) and the baby was born very soon afterwards with the separated placenta following immediately, baby lively and cried, so on one level I feel I'm speaking from a position of inexperience in encountering them these days. Home birthing mothers have usually been in fairly upright positions and mostly rather relaxed in-between contractions. Their neuro-matrix of dealing with labour pain very effective (I read that interesting article in the last MIDIRS).
I also believe most term babies have resources/processes to face birth otherwise human beings wouldn't reproduce as successfully as we do. What those processes are? I believe we certainly don't understand them but "biophysiological feedback" could be one fancy name to give it, to describe e.g. the slowing down of contractions when the baby needs a resting phase or hormonal impulses creating expulsive effort if the baby needs to be born in order to survive? Of course, if we can prove this one we can challenge the use of artificial syntocinon for once and all!
The other aspects of this issue is that experienced midwives have
concerns about the frequency of auscultation that often interferes
with women's instinctive positions and therefore prompts the
question-Is any type of monitoring iatrogenic? And of course many
mothers find the monitoring aspect very disturbing and prefer not
to have it done much or at all.
Thanks for your response; really interesting about what you say
about only being called for a second bradycardia of more than 4
minutes... I wonder what that was based on?!! Has anyone else
worked where that is the case, I wonder? There is certainly
get a bradycardia from sinciput pressure - like when a OP baby
rotates you often get a deep bradycardia which then settles once
the baby is comfortable again; or a baby that comes really quickly
through the birth canal so gets strong compression quickly. I
really agree with you that a healthy baby has all kinds of
resources to withstand that easily.
[from someone whose wife had an unnecessary cesarean]
You ask if you can accurately diagnose fetal distress on the sole merit of an internal monitor. While a properly attached internal monitor may produce a more consistent and/or reliable indication of the fetal heart rate, its diagnostic value in determining the existence of fetal distress is not significantly different from that of an external EFM. Your question might just as well be phrased, can fetal distress be reliably diagnosed on the basis of a fetal heart monitor reading alone.
First, fetal distress is a diagnosis without a definition; there is no agreement on what constitutes fetal distress. Second, there exists no algorithm for using an FHM to identify fetal distress, i.e., there are no objective standards for interpreting FHM tracings and little consistency between practitioners. Third, it would be a breach of standard practice to base a decision to perform a cesarean SOLELY upon a FHM tracing; other contemporaneous observations are usually needed (a) to eliminate other possible explanations for the apparent abnormality (e.g., physical activities by the mother, a loose contact), and (b) to confirm the tracing indication (e.g., attempts to effect recovery by changing the mother's position, and performing a fetal scalp test). Fourth, it is extremely easy to manipulate FHM readings and we personally know of a case in which this was attempted immediately prior to surgery (our own). You can get some really great fluctuations in a tracing by flipping a woman onto her back, sitting her up, pushing her back down, letting her rest several seconds and flipping her up again.
The question you ask is one which my wife and I have had to find answers to in pressing our lawsuit for, you guessed it, an unnecessary emergency cesarean. According to all of the texts and guidelines I have read, the answer to your question should be a resounding 'No'. In fact, many authorities specifically advise against using EFHM on young, healthy women who have no problem pregnancies and no prior history of birthing difficulty (like most first time mothers) precisely because the use of EFHM significantly increases the risk of misdiagnosing fetal distress and performing an unnecessary surgical delivery (aka a cesarean). Many midwives oppose the use of EFHM not only because of its limited diagnostic value but because it limits the woman's mobility and is a potentially stressful distraction. Nevertheless, I have already seen a response to your question assuring you that the monitor tracing is indeed a life saving diagnostic device.
When all is said and done about the diagnostic value of electronic fetal heart monitoring, it really comes down to a statement I received from an experienced expert witness who declined to review our records and unapologetically told us that we didn't have a chance in hell of winning our lawsuit because, "You show me an FHM tracing and I'll show you an excuse for a cesarean."
Personally, I strongly suspect that fetal heart monitors are more
useful to doctors and lawyers in the courtroom than they are to
mothers and babies in the delivery room. But that's a diatribe for
another time.
Where FHM tracings truly do have a CYA role is in defending a
decision TO perform a cesarean. They make it virtually impossible
to successfully prove that a cesarean should NOT have been
performed.
This, of course, is utterly false and A strip showing the
presence of good variability and spontaneous accelerations would
provide extremely sound evidence against the need to have
performed a c-section.
You are, of course, completely correct in your assumption that I have a "questionable understanding of tracings." In fact, I seriously doubt that anyone has anything more than a questionable understanding of tracings. I base this statement upon the lack of diagnostic definitions and standards, on research showing a lack of consistency between OB/GYN's in interpreting tracings which is independent of training and experience, on research showing that FHM are poor predictors of outcome, and on published statements of the NIH, and other such organizations. And last and least, I base it on conversations with purported experts themselves. Perhaps you could suggest a text on the subject which both affords a good understanding of tracings and accounts for the discordant diversity of opinion regarding the value of the FHM.
You are, again, similarly correct in your assertion that a picture perfect tracing containing nothing which anyone would consider irregular and which accorded with every practitioner's idea of "good variability and spontaneous accelerations" would be "extremely sound evidence" that a cesarean was not needed. But realistically, where do you expect to find such a tracing? I am sure that even you would agree that such pristine tracings are rare in the real world, even if you include the miles of tracings generated by women who do NOT have a cesarean.
As it has been explained to me, tracings need to be diagnosed in the light of contemporaneous circumstances because FHM tracings can be affected by such mundane external factors as a laboring women's decision to turn over, sit up, or go to the bathroom -which, is but a small part of a laboring woman's repertoire of movements. And, this vulnerability to external factors also makes FHM tracings subject to both deliberate and incidental manipulation, a point which I raised and had in mind because of the specific facts of our lawsuit.
My claim about the CYA value of tracings was really a speculative
assertion since the courts are hardly inundated with cases
alleging an unnecessary cesarean. It is an extrapolation from the
fact that the emotional and physical impact of prepping a woman
for emergency surgery by itself can be sufficient to generate
tracing irregularities. If this is so then it follows that the
final few minutes of tracing chaos preceding the performance of an
unnecessary stat surgical delivery will likely be ambiguous. It is
this ambiguity which affords CYA protection. Jurors are unlikely
to impose liability upon a practitioner for what s/he can
"reasonably" claim to have believed was a justified response to a
potentially dangerous situation supported by the tracing
"evidence" generated by the prepping process itself--especially if
there are no other injuries to the woman and child. I am sorry for
not making my chain of reasoning clear.
One of my clients is reporting that her baby (in utero) appears
to be exhibiting the Moro reflex from time to time. She said
she felt this a lot with her previous baby, who was grunting,
tachy, needed oxygen, etc. and stayed in the hospital for a week,
although all tests were negative. She says she's felt this
baby do it just once. How worried should I be?
I had a client who reported something similar, and then, after
the baby was born, she told me she had figured out that it was
just that involuntary jerking that sometimes happens as you're
falling asleep.
A baby on EFM during a seizure exhibits a repetitive variable
decel with low points every 30-60 seconds. Moms may feel or
describe them as hiccups, fits or seizures. Jerky head
movements noted on ultrasound are considered diagnostic for
seizure.
Rapid
fetal
hypoxia test developed - Source: University of Warwick
[2/22/06]
[from ob-gyn-l]
If I saw persistent late decels, good variability, and had a
woman with a cervix closed and posterior, I would not sit and
watch her get a fetus in trouble. If I saw the same pattern and
thought delivery were coming within an hour or two, I would wait.
If the situation were intermediate, then I would do a scalp pH;
the result would hopefully allow me the time to wait and watch.
Richard Perkins point (during training) was that there are fetal monitoring patterns that correlate with various states of fetal oxygenation and acid/base status, and that it is possible to act on the monitor tracing alone.
A late deceleration pattern that persists, but where variability is preserved, signifies relative hypoxia. This is why the pattern can often be eradicated with supplemental O2.
As the hypoxia persists and metabolic by-products accumulate, acidosis develops, and a gradual loss of variability is seen in the fetal heart rate pattern. Thus, with a normal baseline heart rate, the subtle "late" decel with a flat baseline is MUCH more ominous than the obvious and large one with good variability.
Baseline fetal heart rate is another important factor which has not been mentioned in this context, but provides insight into the acid/base status of the fetus. As acidosis persists and deepens, the fetal heart will develop a tachycardic response. So persistent tachycardia, subtle late decelerations, flat baseline with absent variability are the signs of a preterminal baby.
So I feel justified in observing patients who present in early
labor with minor signs of compromise, without subjecting the fetus
to scalp pH sampling. But if we cannot alter the pattern by
position, fluids, or oxygen, and signs of acidosis develop,...baby
it's time to cut. I also think it's important to get cord blood
gasses at the time of C-section in situations like this, just to
document that the delivery was timely.
Interesting comments on fetal scalp sampling; I would like the
reference. I have recently served on some Malpractice Tribunals
where with Decelerations the Expert witness stated that a scalp pH
should have been done. We're damned if we do and damned if we
don't
The article ref. is Obstet Gynecol 1994;83:971-4. The title is
Elimination of fetal scalp blood sampling on a large clinical
service. The last author is Dick Paul and it is from USC. They
have always been proponents of scalp sampling.
I think all midwifery programs should include a short piece about how Doppler ultrasound devices work, because it's the only use I've ever found for my high school physics class.
Stethoscopes don't amplify the sound . . . they just conduct it to your ear as efficiently as possible over a distance by providing a channel for the soundwaves to travel without interference and by eliminating outside sounds from your ear.
You can purchase amplifying stethoscopes. I purchased the HP Stethos, "a fully electronic stethoscope which amplifies heart and other biological sounds up to 14 times that of acoustic stethoscopes." I don't know what to say other than that I could hear bowel sounds really, really well with it, but I could still hear the baby's heart better just with my ear against her belly. So I returned it.
A Doppler U/S does not really have anything to do with what we call sound, i.e. energy that travels in the range that is audible to humans. It continuously emits and receives ultrasound energy and analyzes the echo from the emission, just like radar. A stationery object in an ultrasound field will return a constant echo . . . an object moving towards the Doppler will yield an increasing frequency in the echo, and an object moving away from the Doppler yields a decreasing frequency. [Read more about "the Doppler effect".]
So the Doppler actually detects movement, not sound. But since we're using it to "listen" to the baby's heart, and because generating sound signals is lots easier than generating visual images, our little hand-held Dopplers translate the movement into sound.
That's why the Doppler will pick up the "beat" from blood pulsing anywhere inside the mom's belly, whether it's the pulsing of blood through the umbilical cord or the large vessels of the placenta or the baby's body, or the mom's uterine arteries. You can also "hear" baby's movement, large fluid pockets and the placental souffle. That's also why you can use your Doppler to locate the baby's heart exactly . . . the movement of the heart chambers is more complicated than the pulsing of blood, so you kind of hear multiple components to each beat. (I love my little Medasonics Blue Beat . . . it gives me good enough feedback that I can really be sure of where the heart is . . . this helps me confirm vertex and anterior when I arrive at a labor.)
So, no, Dopplers aren't just amplifying the sound of the baby's
beating heart, which is what many pregnant women seem to be misled
to think.
Sadly, this technology proved not to be an improvement over heartrate-based monitoring.
Fetal
Pulse
Oximetry and Cesarean Delivery from the New England Journal
of Medicine
Here are the original announcements:
FDA OKs First Fetal Oxygen Monitor - May 16, 2000 - Obstetricians are about to get the first fetal monitor to measure the oxygen level inside an unborn baby's blood during labor. This breakthrough device promises to help doctors determine which babies really are in distress and may need to be delivered by Caesarean section.
There's finally a better way - moms can listen to their baby's heartbeat without exposing baby to ultrasound, and providers can do non-stress tests without having to argue with the moms! The Fetalphon Antepartum Monitor is "A passive, low-cost, portable phonocardiographic fetal heart rate measuring instrument especially for long-term or continuous fetal monitoring even at home. Fetalphon is a unique monitoring device, free of ultrasound or any other radiation emissions." It's basically a very fancy electronic ear.
I would certainly get this if I were in a multi-midwife practice or at a birth center, for NST's at least! What a relief for both the moms and the babies not to have to worry about ultrasound exposure.
Here's the patent
description - US Patent No.: US 6,245,025 B1, Date of
Patent: Jun. 12, 2001
I think these electronic stethoscopes are an interesting
alternative to exposing the fetus to ultrasound for listening to
the heart beat. However, my personal experience with one of
them was very disappointing. Please e-mail me
about your experiences in using any of these for auscultation of
fetal heart tones. Thanks.
The 3M Littmann
Model
4000 is the next generation in electronic stethoscopes.
The HP Stethos
is a fully electronic stethoscope which amplifies heart and other
biological sounds up to 14 times that of acoustic stethoscopes.
The Electromax
Electronic
Stethoscope by Labtron "offers electronically amplified
sound of 50db at 100Hz.
[NOTE - This link is out of date . . . this may have been a
predecessor to the Fetalphon.]
The SONOPTOSCOPE
claims to be "very useful in the obstetric department since it may
be used to listen to foetal heart sounds."
As of August, 2000, it "is still undergoing FDA analysis for approval prior to sales commencing in the US. I anticipate approval by the FDA in the near future." They have not done any formal testing to assess how early the fetal heart sounds can be detected.