Traditional Healers, External Fetal Monitoring, and the NICHD
Continuous fetal heart rate monitoring is at its core an almost laughable idea. We are checking a single vital sign and using that vital sign to extrapolate a host of ideas and meanings. OBs that have read strips for years can make some sense of them, but would we give so much meaning to any other single vital sign? Would we do it with an adult? Of course not, but there are people who do. In fact, there are entire countries where this is a major methodology for determining the etiology of illnesses.
But the people doing this are not physicians – they are the healers of various cultures. Throughout the world there are practitioners who claim to divinate illness through feeling a person’s pulse for several minutes. This is particularly prominent in Asia. They describe using the rate, strength, and character of the pulse to make all manner of determinations. This practice is fairly laughable to physicians, as it seems crazy to get so much meaning from feeling someone’s pulse.
But is this so much different than EFM? In fact its quite similar. Given that traditional healers are probably hit and miss with their diagnoses, its no surprise that EFM technology is similarly lacking.
Beyond the fundamental issues of divining information from a single vital sign, EFM also suffers from great interobserver variability. Just as a different mystic might think different things from feeling one’s pulse, different practitioners may interpret the same strip differently. In test performance terms, EFM has a small Kappa, where the larger a Kappa is the more the observers agree.
Not only do different practitioners interpret strips differently, they describe them differently as well. Some people call a late deceleration purely based on position relative to the contraction, while some consider a variable looking decel post contraction to still be a variable. Some people infer meaning from the variability during a deceleration, while others think this is inappropriate.
Recognizing these issues, the NICHD issued a new set of guidelines in 2008, defining how we should all describe our strips. Finally, we have a clear direction on how we should interpret strips! Or do we?
The NICHD guidelines categorizes strips into three categories, which basically boil down to:
Category I – strip’s fine
Category III – strip’s really really bad
Category II – everything else.
More specifically the categories (importantly, in the same order) are:
Category I:
Rate: 110-160
Variability: moderate
Late or variable decelerations: absent
Early decelerations: present or absent
Accelerations: present or absent.
Category III:
Variability: absent
and at least one of:
Late decelerations: present and recurrent
Variable decelerations: present and recurrent
Fetal bradycardia
OR
Sinusoidal pattern.
Category II: everything that is not Cat 1 or Cat 3:
Rate: bradycardia but without absent variability OR tachycardia
Variability: Minimal, absent but without decelerations, or marked variability
Accelerations: Absence of induced accelerations after fetal stimulation
Decelerations:
Recurrent variable decelerations accompanied by minimal or moderate variability
Prolonged deceleration >= 2 minutes but < 10 minutes
Recurrent late decelerations with moderate baseline variability
Variable decelerations with other characteristics, such as slow return to baseline, “overshoots” and “shoulders”
So how does this help us?
On the good side, it does help us to be more clear on our documentation, and helps us to be in more agreement on how we are going to categorize strips. We should all be able to agree what is a Cat 1, Cat 2, or Cat 3.
But other that that, its not terrible helpful. This is because Cat 1 is such a good strip that we all would have called it good, and Cat 3 is such a horrible strip that we all would have done an urgent cesarean delivery. The problems is that everything else is Cat 2.
Just about any strip can be Cat 2, from a baby that is just sleeping to one that is having recurrent hypoxic events that just haven’t decompensated yet. Ultimately, Cat 2 is just about any strip that we would disagree about. Some Cat 2s are clearly benign, and some are clearly precursors to Cat 3 strips, but most are somewhere in the middle.
So while the NICHD criteria makes it easier to document, it doesn’t really tell us what to do, because all the indecision is in that big category II.
So is there a better future to our electronic Indian Healer machine?
Probably, but its more likely to be a new technology than a new way to interpret what we have now. This new technology may be STAN monitoring, or ST segment interpretation of the fetal EKG. Like a full EKG, STAN not only looks at the heart rate but also at the movement of the electricity waveform in the fetal heart. STAN does computer analysis of the ST segment, in the same way that we look at ST segments in adults with concern for heart attacks. So far, the technology has been very promising in early trials in Europe, and in one study the center that implemented the technology cesarean rates for abnormal strips had decreased cesarean deliveries and a decreased number of infants born with cord pH < 7.05. However, the jury is still out, and there are a number of issues to still work out.
Like all things, the US is far behind in getting this technology. For better or for worse, the FDA requires a great deal more data than is required in Europe before this can be put into play. If STAN works out in Europe, likely we will see it in use in the US in the next 3-7 years. If STAN is a bust, as fetal pulse oximetry was in the 2000s, we may never see it here.
Either way, we’ll just keep reading the fetal heart rate tea leaves.
Academic OB/GYN 
First, an on point comment — I’d love to see more data on CFM. I had it during my first labor, and while it wasn’t earth shattering, it was annoying. (Especially when the machine ran out of paper and it kept sounding an alarm until my physician father turned it off and replaced the paper b/c the nurses didn’t come to deal with it!!! NB: This is the only complaint about my nurses — they rocked.) So I’d love to see a more reasonable approach to it by hospitals. As I head into a second pregnancy and labor, do you have suggestions about how to bring this up with my OBs in a way that will not offend them?
Totally off point, but something I want to see discussed — I cross posted this question at Skeptical OB —
One area I was very unhappy with my obstetric care was breastfeeding. It seems like it is an area where there’s no one to treat the mother. The ped treats the baby, the ob treats the mother’s uterus, etc., but no one is there for real nursing problems. I did successfully nurse (exclusively for 5 mos, slowly introducing food thereafter, formula at 9mos), but it was a constant battle.
I was the woman with legitimate supply problems. But there was no one to run tests to tell me WHY. (Hormonal imbalance? Some other reason?) We ruled out latch, suck, frequency of feeds with help from an LC and (god help me) … LLL, but something was definitely wrong. DD only gained a pound in her first 5 weeks, and the hospital LC wanted me supplementing her off the bat, which I resisted with support from DD’s pediatrician. She only gained 5 oz between 4 and 5 months, which led to the early introduction of solids. Reglan definitely helped, but I didn’t like the risks and the fact that it’s an off label use. The OB said “some women don’t make enough.” Ok, I’ll accept that. But WHY? And what can we do about it?
Can you explain to me who should be helping with this type of problem? And what the problem might be so I know what questions to ask if it happens again?
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>> As I head into a second pregnancy and labor, do you have suggestions about how to bring this up with my OBs in a way that will not offend them?
I don’t think most OBs would be offended by any patient’s desire to avoid continuous monitoring, as long as the pregnancy was low risk and the labor was not being induced or augmented and there was no epidural in use.
The hospital, on the other hand, may be a different matter. Some hospitals have internal policies for continuous monitoring in all labors (not really justified). One would have to look into this ahead of time. Many hospitals do allow intermittent monitoring in low risk non-induced labors.
Monitoring does have some benefit for the patient, but in low risk labors it largely is a benefit for the hospital. With external monitoring and telemetry, there is less need for 1 to 1 nursing care, which is very expensive for the hospital.
Breastfeeding is a big issue, and I am by no means expert in this area. But in short, I honestly don’t know why some women make less milk than others, or any reliable way to get those women to make more milk. It is likely genetic variation.
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Dr. Alison Stuebe at UNC has written some great articles on how limited the research is, including this blog post:
https://bfmed.wordpress.com/2010/04/24/when-lactation-doesnt-work/
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csmommy, I suggest reading The Breastfeeding Mother’s Guide to Making More Milk, by Lisa Marasco and Diana West. Both are IBCLCs with strong experience in the area of low milk supply. It may not answer your questions, but it may give you some ideas of why your milk supply was low and what you may be able to do about it next time, if there is a next time.
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Should it be used continously or intermittently?
How often does it work? I used it intermittently and didn’t have a problem, but my friend had it continuously and the nurse spent literally 25 minutes out of every hour adjusting the thing to get a good read. It was torture for my friend who was trying to go without pain medication. Also, the doctor said a good pattern had been established for her labor, but I could see by watching her that the contractions were only about 45 seconds long and 8 minutes apart, not what the machine was saying at all. In short, the thing didn’t work half the time. Then they put the IUPC in and that didn’t work either, even after fiddling with it for an hour. They also did a BPP and got a score of two, but she had a 24 hour labor with no meconium and no decels on pit, followed by a cesarean for OP and FTP, so I’m wondering how accurate the BPP are as well.
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>> Should it be used continously or intermittently?
In low risk labors without pitocin or epidural, intermittent monitoring is fine. Intermittent auscultation has also been shown to be adequate, though in my opinion there is no reason to favor this over a intermittent monitoring, which is far easier in the hospital environment.
>> How often does it work?
It all depends on what you mean by “work”. Monitoring is very sensitive but not very specific, which means that it is very effective in detecting fetuses that are in jeopardy, but that of all the fetuses it detects, only a small subset actually are in jeopardy. So if the goal is to find every fetus that may be in danger, it works nearly perfectly. If the goal is to find only those fetuses, it doesn’t work very well.
That’s why monitoring performs better in high risk situations than in low risk. Any test performs better in a higher prevalence situation (where there is more of the condition you are looking for). In high risk situations it is more likely the baby will not tolerate the labor, and so when the monitor says there is a problem, it is much more likely that this is a true positive rather than a false positive test. In very low risk situations where there are very few fetuses that will be injured in labor, the same abnormal fetal heart rate tracing we saw in the high risk case has a much higher likelihood of being a false positive test.
You are right that tocometry (contraction monitoring) is less accurate than the fetal heart rate tracing. The external tocodynamometer (toco for short) is just a spring gauge on a little analog to digital converter packaged into a little disc. You squeeze the thing and the line goes up. As such, what you see on the screen is highly dependent on many factors such as the placement of the monitor, maternal habitus, strength of contraction, and fetal position. When they are picking up well they still do not accurately measure contraction strength, just relative strength compared to other contractions. True contraction strength measurement can only be done with an internal monitor, which also can be finicky, as you mentioned.
BPP in labor is something that not everybody does. There are some data on this, but its not in widespread use. You mention that your friend’s BPP was 2, but didn’t mention the outcome. If the baby was born with a bad cord gas (acidotic pH) and low apgars, the BPP was accurate. If the baby was born crying and pink, it was wrong.
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Well, everyone around here (rural michigan) does BPP at 41 weeks, and low fluid is a common diagnosis. I don’t know what the cord pH was, but the apgars were 8 and 9. I had heard that EFM wasn’t that good at determining stress on the baby, but I was surprised that they couldn’t find the heartbeat at all so much of the time, without fiddling with it.
One local hospital has telemetry for cEFM. That sounds much better than being so confined.
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I think we’re talking about two different things, or maybe I confused the meaning of the first comment.
BPP as a measure of ongoing fetal well being in the antepartum period (as you describe it being used at 41 weeks) is a well accepted practice and is used by everyone.
BPP as a measure of fetal well being _in labor_ is something that not everybody does.
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Sorry, yes, my wording in the first post wasn’t clear. Regardless, I suspected in her case, the BPP wasn’t accurate, because after induction, her water broke on its own 12 hours later (lots of water, but I have nothing to compare it to), no meconium (and that midwife looked for a good 15 minutes under a bright light), the baby never had any decels. I didn’t think about apgars, but those were fine as well. Anyway, my point is that the technology (ultrasound, iupc, toco, efm) seems to offer a lot of false positives, and yet some have complete faith in it.
Hope I didn’t find this link here:
http://www.kevinmd.com/blog/2010/07/unnecessary-testing-tort-reform-cure.html
From this, I’m guessing the problem isn’t exclusive to obstetrics:
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So on to this STAN technology…my first reaction when I learned of it’s existence was a huge internal groan…I was envisioning every laboring women hooked up to this in labor floors all over the country. Despite the fact that it’s intention is to better analyze potentially “bad” strips to (hopefully) avoid operative births, I can say that many of my physician colleagues would be throwing that ST monitor on every woman that crosses their path.
The argument for ST technology w/ EFM is pretty convincing if it is used properly. A conference I attended discussed this in a case study format with pretty convincing results. One of the “bad” strips (ie, what usually would fall into Cat 2) in which most physicians I work with would immediately section a woman for was reviewed with it’s concurrent ST segment tracing. The ST segment was very reassuring despite the traditional EFM strip looking “bad”. The woman in this particular case went on to have a normal delivery with a newborn with good apgars. I believe that a large US study was underway on this- but don’t quote me. It will be interesting to see how long it takes for this to catch on, if it even does!
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Hunh, I didn’t know I was so out of the loop — how is ST technology used? Does it require an FSE?
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A fetal scalp electrode records the fetal cardiac waveform and a computer continuously analyzes rate changes and ST segment depression or elevation. The computer uses this information to predict fetal hypoxia. In some interations, the computer has a green light, yellow light, red light readout. In a recent study low cord pHs were almost eliminated without increasing cesarean rates.
In its current incarnation, the technology is only used when the regular EFM has a concerning strip.
PubMed STAN and you’ll find a bunch of articles. It is starting to gain traction in Europe, but is not being used in the US yet.
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The problem I would have with it is the fact it needs an FSE. I think this will lead to more invasive monitoring on low risk patients, not less. I can understand this being considered on Cat II strips. But, I know of a major hospital in the area that was already doing AROM and using internal monitoring on all mothers, even the low risk ones, and there was definitely morbidity (and even two cases of fetal mortality due to disseminated herpes).
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First, I just want to say that your posts have me laughing out loud ~ “Either way, we’ll just keep reading the fetal heart rate tea leaves.” ~ Bahahahaha!!
Second, I wanted to know your thoughts on how continuous fetal monitoring may actually cause complications. Theoretically, if a pregnant woman is receiving continuous monitoring, she must remain laying in a hospital bed and is not free to move and position herself to what is comfortable/feels natural. Often women end up laboring on their backs, which is very restricting and painful (speaking from experience), but more importantly could cause complications, correct? I know that I have always been told not to sleep on my back due to it restricting oxygen/blood flow to the baby. Couldn’t this intervention (fetal monitoring) be signaling an emergency when really it was the cause of the emergency to begin with? Also, would you agree that continuous fetal monitoring would increase the occurrence of a laboring mom to receive an epidural (often followed by pitocin) because of the increased pain level with little “wiggle room” to manage it? Would love to hear your thoughts! 🙂
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Debbie –
Thanks for the comment. I really don’t think that one could rationally attribute a fetal emergency to fetal monitoring itself. Fetal monitoring does sometimes pick up issues that ultimately turn out to be non-threatening, however.
As for laying in bed, I think this is something that the natural birth community feels strongly about but that lacks any rigorous data to support. Most of the patients in my hospital get epidurals because they don’t like the pain of labor. Most of them are not culturated to the idea that there is an existential benefit to enduring pain. A minority of women in my community, and a greater number in other communities, prefer the mobility gained from declining an epidural and choose to address the pain of labor in other ways.
Being on one’s back does decrease the blood flow to the pregnancy, but in a healthy pregnancy with a healthy placenta that does not appear to affect the fetus. Fetal monitoring strips remain unchanged with women on their back, in most situations. Pregnancies with bad placentas (bad diabetes, pre-eclampsia,etc) may be more affected by maternal position. Ultimately though we can detect these issues with fetal monitoring, as a fetus not getting enough blood flow will have recognizable fetal heart rate patterns. Its a very useful technology in some situations.
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