There are a handful of situations in which a planned cesarean section is more likely at the end of your pregnancy. One of those is if your baby is breech, which means their body is not in a head-down position. In most cases, if this happens, a C-section will be the default.
That said, if you have a breech baby, you may have some options. Your care provider may attempt to turn the baby through a procedure called an external cephalic version, or ECV. And if ECV doesn’t work or it’s not available, you may be offered the choice between a planned C-section or an attempt at vaginal delivery.
Let’s review the data to help you feel more informed and prepared in discussions with your doctor.
What is a breech baby?
The majority of babies come out headfirst during a vaginal birth. A breech baby is one who is not head-down in utero and, instead, some other body part would come out first during delivery. The baby could be in a number of different positions, as illustrated below.
First: a bit of reassurance. People often express concern that a baby being breech is a sign of some broader issue. While it is true that some fetal complications increase the risk of a breech delivery, they are things you would know about from ultrasounds and prenatal testing. Other than the questions about birthing, breech position isn’t generally a cause for concern.
A second piece of reassurance is that babies who are breech do often turn on their own. In one study, 57% of babies who were breech at 32 weeks — and 25% of those who were still breech at 36 weeks — had turned head-down by delivery. Even after 37 weeks, some babies turn on their own.
If the baby doesn’t turn on their own and the pregnancy is at term (after 37 weeks), there are two central questions:
- Should you try to turn the baby with an ECV?
- If the baby isn’t turned (either you do not try or it doesn’t work), should you plan a C-section or try a vaginal delivery?
What is ECV?
An external cephalic version is a procedure that is performed at or close to term in which the doctor attempts to turn the baby from the outside. Broadly, it involves applying cornstarch or gel over the abdomen and then using hands to try to somersault the baby either backward or forward in the uterus. (Apparently some providers prefer backward, some forward.)
An ECV is successful about half the time. We know this from randomized trials and meta-analyses of both randomized and non-randomized data. The largest meta-analysis is based on about 185,000 breech pregnancies, so it’s quite precise. There are some factors that decrease the chance of success, including it being your first child, low amniotic fluid, and “firm abdominal muscles.”
The risks to the procedure appear to be low, so it is typical to offer it to women if they are interested in a vaginal birth and the fetus is still breech at 37 weeks.
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.
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 after an ECV to rate the pain they’d experienced 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.
Are there alternatives to ECV?
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 a specific toe (an “acupoint”). 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 around your toes do not have any known downsides (smelly toes?), but they are not evidence-based solutions.
How do you deliver a breech baby?
Let’s move now to the case where an ECV either didn’t work or wasn’t available. What is the right approach to delivery?
To think about this, it’s useful to start with why breech delivery is more complicated. The basic issue is that an infant’s head is very large. If that comes out first, there is a high level of confidence that the rest of the baby will be able to fit through the cervix (i.e. that it is sufficiently open for that to happen). In a breech presentation, something other than the head would come through first.
In some cases, this is extremely dangerous. If, for example, a leg came through first, that could happen before the cervix was dilated enough for the baby. This is risky. In other presentations — as in “frank breech,” where the butt is first (think of the baby as folded at the middle) — there is less of this concern, because the first part through would still be large. As a result, it’s much less likely that the head would be stuck.
Even if the baby is butt-down, it is more complicated to deliver a breech baby than one with their head down. The delivery procedure involves (typically) one leg at a time, then the arms, then the head. There are various maneuvers, with names like the Mauriceau-Smellie-Veit maneuver and the Bracht maneuver, that may or may not be used.
In summary: On one hand, delivering a breech baby is more complicated on average and requires an additional knowledge base. On the other hand, it is also definitely possible, at least in some cases.
Given that it is possible to deliver some breech babies vaginally but also that it seems like it might entail a higher risk, a number of randomized trials have evaluated whether it is safer for a pregnancy to try a vaginal birth with a breech baby or to plan a C-section. The best-known of these is the Term Breech Trial, published in 2000 in The Lancet. In this trial, 2,088 women with breech pregnancies at 37 weeks were randomly assigned to either a scheduled C-section or a trial of vaginal labor. The main outcomes studied were complications for the infant.
The headline finding was that neonatal mortality was lower for the planned cesarean birth group than for the planned vaginal birth group. This finding has been echoed in other trials, and a 2015 meta-analysis shows a similar overall pattern. The differences in risk are small in absolute terms, and follow-up of these studies finds no differences in outcomes for children, but there does seem to be a small advantage to planned C-sections.
The Term Breech Trial had a huge impact on clinical practice. Following that trial, there was an increase in the use of C-sections for breech births. The evidence-based guidance was that breech deliveries should be delivered by C-section in most or all cases.
What this means is that the default choice, at this point, is a C-section for breech deliveries. The question arises, though: Is it possible to try a vaginal birth?
The evidence says yes, with some caveats. For data, we can look to the PREMODA study in Europe. This study wasn’t randomized, but the researchers followed women who planned a vaginal birth with a breech delivery and those who planned a C-section. They found that there were no significant differences in outcomes in the two groups and that 71% of the planned vaginal deliveries did happen vaginally. The study concluded that, in some circumstances, a vaginal delivery may be possible.
I say “caveats” because, first, the criteria for a vaginal birth to be a possibility in this study were fairly strict. They included normal pelvic size, as assessed by x-ray; no fetal head hyperextension (on ultrasound); a fetal weight of 2,500 to 3,800 grams (smaller than about 8.5 pounds); and frank breech presentation. In general, if this is an option, it will be one only under very favorable circumstances. Effectively, anything that puts you in a higher-risk group (e.g. large fetus, any complications) will make it unlikely to be an option.
A final issue, especially in the U.S., is provider experience. Because C-sections have become the default in breech births, not all providers are familiar with breech vaginal deliveries. Experience can really matter, especially since, as noted at the top, the procedure is slightly more complex. If you want to pursue this option, you may need to seek out a provider who does it more often. That can be hard at the last minute.
The bottom line
- If your baby is breech at around 32 weeks, try not to worry too much — more than half of cases will resolve on their own.
- If your baby is still breech at 37 weeks, you have several realistic options: (1) plan a C-section; (2) try an external cephalic version (success rate about 50%) and, if unsuccessful, plan a C-section; or (3) try an ECV and, if unsuccessful, consider a vaginal birth.
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