A vagina is pretty small relative to the size of a baby’s head. (Man, I love opening with lines like that.) We can all agree that it’s hard to see how a big ol’ noggin will squeeze out of a modest little crevice at the best of times. It’s understandable, then, that any birthing person and their partner would agree with having a surgical birth if a care provider recommends it due to an “incompatibly” sized baby, right? Not necessarily. How does a care provider know how big the baby is? How accurate are their tools for measurement and how often are they right? Lean in, my friends, and I’ll share the information I’ve found.

Now THAT's a big baby!

Now THAT’s a big baby!

First of all, the jury’s still out on how big a “big” baby actually is. Some say 8 lbs 13 oz and up, others say 9 lbs 15 oz and up. Right off the bat, we’re dealing with ambiguity. Women who have gestational diabetes are historically at risk for having bigger babies, but can reduce that risk by up to half if they undergo treatment for their GB during pregnancy. The risk of injury to the baby and/or the mother is one reason why a care provider would induce or suggest a cesarean. However, evidence shows no more of a correlation between injury from a suspected big baby than from a typically-sized baby. Same thing goes with the risk of a stillbirth – no evidence was found to support that claim.

The size of a baby in utero is notoriously hard to predict. The average accuracy of size estimates can vary from 20-63 percent! Can you believe that?! We can put a human being on the moon, but we still can’t reliably predict how big a baby will be. Let’s just say, though, that a care provider is right about the size of the baby, and wants to induce before that baby gets any bigger (to prevent a cesarean birth). Unfortunately, induction raises the chance of having a c-section significantly. The bottom line is that there is no link between induction and/or elective cesarean for big babies and improved maternal/fetal outcome. I think that’s really the linchpin of this whole thing. For me, the most mind-boggling part of the article where all this information came from was this tidbit: “Women who were suspected of having a big baby (and actually ended up having one) had a triple in the induction rate; more than triple the C-section rate, and a quadrupling of the maternal complication rate, compared to women who were not suspected of having a big baby but who had one anyways.” So basically, everything is hinging on an opinion that is, at best, only correct about six times out of ten. Want more information? Here‘s the full article.

Your Big Baby

So, the evidence shows that we can’t base the decision to induce or perform a cesarean birth on a baby’s estimated size. How do you bring that concern up if the situation warrants it? The last thing anyone wants is to get in a disagreement with their care provider at such a pivotal moment. Here are some things to keep in mind when you’re discussing the possibility of surgical birth due to a big baby:

  • Take your time. If it is a case of your labour “stalling”, and no split-second decisions need to be made, feel free to kick everyone out of the birth room and ask for private time to consider your choices with your partner. While your doctor is waiting, you could even ask them to look at that article linked above. This time-out could be just what you need to get your labour going again!
  • This is your birth. Nobody has the right to tell you what you should do with your body, ever. A good doula (like me) who can remind you of your priorities and give you decision-making prompts will help you maintain your agency throughout this entire experience.
  • Your care provider cares about you. Most people who are in the birth business are there because they love birth and they sincerely care about women and babies. Regardless of whether or not you agree with your care provider, trust that s/he wants the best for you. Acting from this place will allow you to keep an open dialogue.