Saturday, May 15, 2010

Prove me wrong!

Over the past few years, I've been trying to track down a source for a statistic that I am fairly sure doesn't exist. More and more frequently I am hearing from women who've been told the risk of uterine rupture in VBAC is the same as the risk of uterine rupture for a first-time mom, or for an induced first-time mom.

Listen, I am all about putting the risk of rupture into perspective, but just as I hate it when the risks of cesareans are understated or misrepresented, I can't tolerate the same thing from my own camp. Every single source I have been able to find shows rupture risk in VBAC many times higher than risk with an unscarred uterus, regardless of parity, induction of labor, etc. I can not find a single reference in literature to a study showing a 1/2% to 1% risk of rupture in a non-VBAC labor. All I find are dead ends, and data confirming that a uterine scar is the single biggest risk factor for rupture.

I've asked multiple people in multiple forums for a source substantiating this claim, and no one has ever been able to provide one. So I figured I'd ask here too: does anyone have a source that will prove me wrong?


  1. Pam -- in one of the NIH reports, I read that the safety of the baby was the same in a VBAC as for a first time mom, but don't ever remember anything about rupture.

  2. Tracey, yes, the NIH report and at least one recent study show the risk of neonatal mortality is virtually the same for VBACs and for FTMs. That has always made sense to me, since roughly 1 in 2,000 babies will have a worst-case outcome following rupture in a VBAC attempt, and other birth emergencies have far greater impact on neonatal death rates. 1 in 2,000 just isn't adding enough risk to make a statistical difference.

    What troubles me about the rupture rate thing is that it's so similar to what so many activists decry on the other side. Yes, the risk of rupture is LOW in VBACs, but 1 in 200 is still FAR greater than 1 in 7,500 (roughly the rupture rate in unscarred uteri in developed countries), and presenting it as "the same" makes ALL the statistics we talk about look questionable.

    A recently released study that actually broke this out in more detail (another post coming on this one- it's fabulous!). In the study group of over 20,000 total births, there were 5 ruptures: The induced first-time mom group had 1 rupture in 2,028 deliveries, the VBAC group had 3 ruptures in 423 deliveries, and there was 1 rupture in the ERCS group of 1669 deliveries. While the authors of the study say the number of ruptures was too small to achieve overall statistical significance, the rates are consistent with all other data I've been able to find. Still, when I posted the numbers in a FB thread discussing the study, someone replied that she did not believe the difference in rates. A *lot* of people are absolutely convinced that VBAC does not carry an increased risk of uterine rupture. IMO that's dangerous because it suggests that no special care needs to be taken, it encourages women to ignore signs of rupture during labor, and it promotes the very attitudes that (also IMO) helped contribute to the horrific medmal situation surrounding VBAC. When moms are told there's "no risk" and *after* they rupture and have a scary emergency c-section they find out that their risk was, indeed, significantly higher- it's a betrayal. It is horrible when OBs give bad information and ignore evidence to promote their viewpoints. It is just as bad when activists do the same thing.

  3. I felt like standing up and clapping reading this reply! Go Pam!

    I completely agree with you...
    I think the focus has to be kept on accurate information and giving options.

    It's scary when it goes anywhere else.

  4. Oh wow - I just discovered your blog and I guess mentally already put it in the "Nice but probably among the zealots..." pile. And then read this. Thank you. I am planning and hoping for a VBAC, with an incredibly amazing and supportive OB, but I, too, think we do ourselves a dreadful disservice by misrepresenting alternatives when it comes to women's health. I believe in individual choice that is informed and meaningful - whether it's what the "establishment" or the "crunchy contingent" or anyone else thinks is the "best" choice.