Labor Induction, Vaccines and Periods, and More on ECVs
A little something for everyone (I hope!)
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Among the many things that distinguish the newsletter form from traditional journalism is the opportunity to have ongoing conversations. This has happened a lot with COVID, where the evolving situation and new data mean that I frequently revisit the same questions. But it’s true more broadly, and there are often times when I want to do just a bit of follow-up on earlier topics.
Today is one of those posts. It’s a hodgepodge! A decision tool for labor induction. A review of the new evidence on COVID vaccines and periods. And a slightly longer dive into pain management and natural alternatives to an external cephalic version for breech babies. Hopefully you’ll find something in here of interest!
Labor-induction decision tree
One of the most common things I get asked about, on Instagram and elsewhere, is labor induction. In particular, pregnant people wonder whether they should be induced at 39 weeks or if it makes sense to wait; are there risks to induction, or benefits? The question of whether to induce labor has always been present, but a large randomized trial published in 2018 — the ARRIVE trial — changed the calculus for many providers by suggesting that labor induction did not increase the risk of C-section.
I’ve written much more about that trial in this post, but my primary takeaway is that these results should be a part of the discussion though not dispositive. This is an area where shared decision-making is the key to reaching a choice that works for you. But shared decision-making can be hard without a good structure.
Which is why I was very happy to see and share an excellent decision tool, developed by Ann Peralta. Ann has worked in maternal and children’s health for the past 15 years and has a doctorate in public health (DrPH) from Boston University. In her words:
Each year, about 600,000 people in the U.S. have an induction of labor without a medical indication. The American College of Obstetricians and Gynecologists, the American College of Nurse-Midwives, and researchers on all sides of this issue all agree that shared decision-making should be used when counseling pregnant people on this topic. That means they think pregnant people should be informed of their options and the evidence and then they should ultimately decide how their labor starts. But right now, that’s not how many people experience it.
So for my DrPH dissertation project, I tried to make shared decision-making happen on this topic. I formed a core group of providers (an OB, a family medicine physician, and two midwives), and we created an initial prototype of a shared decision-making tool and process. We recruited a larger group of providers (OBs, midwives, and nurse practitioners) to test the tool and process in three languages because we wanted to solve for inequities in who gets to experience shared decision-making. Once the tool was in use, I interviewed a very diverse group of pregnant people who experienced it to get feedback on the tool and assess whether or not shared decision-making was happening. After we had some clear improvement themes from the interviews, we revised the tool and tested the next version.
We did this three times — until we were making very minor changes to it and were hearing consistently positive experiences using the tool. I also talked to providers during each testing cycle. Many of the pregnant people I interviewed described using the tool as “awesome” and “empowering,” and providers said it improved the quality of their care and reduced bias. Our study team is working to publish our process and results in a peer-reviewed journal, but in the meantime, I know a tool on this topic has been called for by many, so we wanted to share it: www.inductiondecisionaid.org
Vaccines and periods
There is a new paper, published last week, on vaccines and menstrual periods. This paper follows up on some previous work and addresses the question of whether periods were heavier/earlier/disrupted by the COVID mRNA vaccines.
The study covers about 39,000 people who were surveyed about their post-vaccination periods. The headline statement is that 42% of people reported heavier menstrual flow after vaccination, 14% reported lighter or no change in flow, and 44% reported no change. The authors also reported breakthrough bleeding among a substantial share (about two-thirds) of the 1,800 people who do not typically menstruate (mostly those who are on long-acting contraceptives like IUDs).
The authors in this paper are very straightforward about what the paper can and cannot accomplish. What they make clear at the end, and I agree is important, is that the sample here is not randomly selected. The authors found their sample through various word of mouth, Twitter, media coverage, etc. (It is possible I advertised it in the newsletter, although I cannot find any evidence!) All of this is to say that the approach to recruitment isn’t random, and as a result it is difficult to draw any conclusions about magnitudes.
Bottom line: it does not seem at all likely to me (or, I think, to the authors) that 42% of women who get the COVID vaccine will have heavier menstrual bleeding. The authors make a strong point about the value of this analysis, noting that while there is no reason to think any menstrual cycle disruptions are a risk, studying it carefully will normalize and reassure women who do experience that. The remaining missing piece is a more systematic understanding of the size of the risks. For that, we’ll need a different sample and likely more questions on standard variability in cycle.
External cephalic version (ECV) follow-up
Several weeks ago, I wrote a post about breech delivery in which I touched on external cephalic version (ECV), a procedure where doctors try to turn a breech baby from the outside. I talked about the success rate (about half) and the risks (low).
There were many follow-up questions, and I wanted to take a chance to answer a few here.
The procedure can be painful. Someone is literally trying to make your baby do a somersault in your uterus. Babies do move around a lot in there, which is usually not very painful, but this is a large movement. In general — although this varies — ECVs are performed without pain medication.
How painful is it? This is a difficult question, because pain is subjective. What we have is evidence in papers like this one, in which women were asked to rate their pain after an ECV on a 10-point scale. The average was 5.7, with less than 5% of women reporting a pain number above 8.5. This definitely suggests that the procedure can generate some pain, but it’s very hard to know what a “5.7” on the pain scale really means.
There are a number of studies that evaluate the use of pain medication for an ECV. One study of nitrous oxide suggested that pain scores were reduced if nitrous was used, but a randomized controlled trial follow-up did not support this. A second pain approach is a short-acting opioid called remifentanil. One randomized trial showed a reduction in pain scores with the use of this drug when pain was evaluated right after the procedure, with no differences 10 minutes later.
Neither pain medication improved or worsened success rates.
These results suggest some possible support for pain relief as an option but aren’t overwhelming. One contributing issue is the short duration of the procedure. A short duration of pain is generally tolerated much better than a longer duration (even if the longer duration is at a lower level), and the possible risks of pain medications may push many providers away from using them.
Spinning babies and moxibustion
The second big follow-up question everyone had was about other approaches to turning breech babies. What about spinning babies (or yoga, or any other approach where you try to use movement to encourage the baby to turn around)? What about moxibustion or acupuncture?
On the general question of whether particular postures or movement can impact position, we have relatively limited data. A meta-analysis of randomized trials on this covers only 417 women and evaluated a variety of techniques (elevated pelvis, knees to chest, etc.). These trials found no evidence suggesting that such positional techniques changed infant presentation, rates of C-section, or Apgar scores. The authors and other commentators note, however, that the samples here are small and that there are no risks to these techniques. There is no reason not to try them.
Moxibustion is a technique in which herbs are burned near the skin. For the correction of breech presentation in particular, the approach is to burn the herbs near one of your toes. Sometimes this is combined with acupuncture.
There are a number of small trials of this approach, with various outcomes and comparison approaches. The Cochrane Review meta-analysis is somewhat unsatisfying since it’s difficult to know quite how to combine everything. In general, when compared with doing nothing, moxibustion does not seem to have an impact. There are a few cases where one small trial showed some effects (for example, one trial showing a reduction in use of oxytocin for labor stimulation after moxibustion). But with so many mixed impacts and such small samples, it’s hard to really hang your hat on anything. What we need here, and do not have, is a large randomized trial, ideally one that would compare moxibustion as directed with “sham” moxibustion that burns herbs in the wrong location, to try to figure out if there is a placebo effect.
Overall conclusion here: ECV — even with a 50% success rate — is far and away the approach with the most evidence of efficacy. Moving around to new positions or burning herbs does not have any known downsides, but they are not the most robust solution.