Lately, I’ve become obsessed by the question “Does childbirth, specifically vaginal childbirth, cause pelvic organ prolapse?”
Most say yes, some say no. I had assumed childbirth causes prolapse. Wouldn’t pushing out a baby compromise your pelvic floor support structures?
Why Do I Care if Childbirth Causes Prolapse?
Personally, I don’t. My past is by definition past (obvious, I know). Regretting something I can’t change is pointless.
However, my friends are a-breeding, and I’d like to give informed advice if asked.
Also, fixations sometimes take hold without any rhyme or reason. I’m done having kids. I can’t explain why this fixation stuck.
However, I do know how it began. I read a blog post. And this blog post quoted a well known source who emphatically declared pregnancy, and presumably childbirth, DOES NOT cause pelvic floor disorder and that women who do kegels are in fact creating pelvic floor disorder. Below is a screenshot of the quote that captivated me:
Wow. That’s a pretty bold statement. I thought “Is that true?” Honestly, most of my brain wanted it to be true because maybe if childbirth doesn’t cause prolapse then unfixable structural problems aren’t to blame. If this is the case, prolapse might easily resolve.
Alas. I’ll save you the suspense. No. Unfortunately, I don’t think that’s true. The question is more complicated.
However, the opposite statement—that childbirth DOES CAUSE pelvic floor disorder and kegels will fix it—isn’t entirely true either. Right now, leave the kegel question aside. I’m sure I’ll unpack that in a future post. [Update: Read In Defense of the Kegel]
Some women buy purses. I buy scholarly articles I probably have no business reading. Although I’m overeducated (completed my MA and spent 2 years pursuing a PhD), I went to school for (ahem) English, and I was deconstructing 19th century novels, not exactly the academic training ground for searching Pubmed or questioning science-y folks. Still, text is text. Let us plough ahead.
Yeah, me too. I’ll try to clarify. First, pelvic floor disorder is a super vague term. Pelvic organ prolapse is a kind of pelvic floor disorder, but not all pelvic floor disorder is pelvic organ prolapse. For example, urinary incontinence and fecal incontinence are pelvic floor disorders that often appear independent of pelvic organ prolapse.
Nevertheless, since pelvic organ prolapse (POP) is a large component of pelvic floor disorder (PFD), I’ll narrow the discussion to prolapse. But keep in mind, POP and PFD overlap without being synonyms. Therefore, my critique of the above quote is tangential. Literally, childbirth does not cause PFD. What do I mean by this?
If you read Is Your Vagina Falling Out? you’ll remember that “cause” and “risk factor” need to be separated. Causes are hard to pinpoint. Risk factors are more important.
Therefore, I’m rephrasing and narrowing the debate. That might not be fair, but, without precision, I’m all over the place. This means we are leaving PFD behind and venturing into a more pointed question:
Is Vaginal Childbirth a Major Risk Factor for Pelvic Organ Prolapse?
Yes. And, it depends.
The Argument that Childbirth is Not a Risk Factor for Pelvic Organ Prolapse
Those who argue that childbirth does not cause (and therefore imply is not a major risk factor for) POP note the prevalence of PFD among nulliparous women (women who haven’t given birth). Specifically, they say nulliparous women have rates of incontinence equal to their birthing brethren. Compelling. Is that true?
The Nun Study
“The nun study” is the de facto evidence for this argument. I was curious, so I looked it up. And glory of glories, it is not behind a paywall (Google the title of the study to find the pdf). Hallelujah.
The researchers “conducted a survey of nulliparous, postmenopausal women with regard to the prevalence of urinary incontinence.” They say the purpose of this survey “was to determine the prevalence of urinary incontinence symptoms in a nulliparous population, so as to evaluate the effect of aging without the effect of childbirth.” Sidenote: Scientists are wordy.
This is interesting. About half of the nuns were incontinent. BUT their incontinence does not answer the question “does childbirth cause prolapse,” and therefore is not evidence against an unasked question.
I like the nun study. It was interesting. It just doesn’t prove all that much.
The study’s limitations:
- Only 149 nuns were surveyed. That may be a decent sample size, but I’m not sure how representative it is of all nulliparous women. A statistician could provide more insight into that.
- The researchers weren’t comparing the nuns to matronly controls. They were comparing the 149 nuns to population based statistics on parous women. Can they do that? I don’t know. I guess they did.
- They have proven childbirth isn’t necessary for incontinence, but not that childbirth doesn’t cause pelvic organ prolapse. In other words, for my question, they haven’t disproven anything.
- Extrapolating to other population segments is fraught. For example, many parous women with POP may not be incontinent because urinary retention rather than urinary leakage increases as the POP grade increases. Therefore, the most severe cases of PFD via POP might not even have incontinence as the main symptom (but they will have other bothersome symptoms). Leaking urine is not the only measure of PFD and should not stand in for it.
Overall, I walked away from the nun study with new insight into the prevalence of urinary incontinence among women, but not much new info about childbirth and prolapse.
The nun study wasn’t smoking gun evidence that vaginal childbirth does not cause POP. I don’t know what I was expecting. Disproving a negative is famously impossible. But then I came across another source, called Childbirth Connection, refuting the “myth” that vaginal childbirth causes PFD. They reference the nun study again. However, they also make some other, more interesting, arguments.
They say the studies that look at vaginal childbirth and PFD do not take into account the type of childbirth. They also say c-sections will not reduce PFD. They provide links to systematic reviews, but the links just kept on bringing me to an error page, so I wasn’t able to read them. Bummer.
Their point about the risks of forcep deliveries, episiotomies, and other operative vaginal birth procedures makes sense. They also criticize the rates of fundal pressure and supine birthing. Taking some of their research on faith (which I am loathe to do), the type of vaginal birth you have may matter more as a risk factor than if you have a vaginal birth. This isn’t a revolutionary statement. But it is a helpful one.
Still, vaginal birth is as vaginal birth does. If your vaginal birth was of the higher risk variety, I wouldn’t call vaginal birth as risk factor a myth. I would simply concede it is a more nuanced risk factor than usually appreciated (a nuanced, yet essential risk factor).
The C-Section Rabbit Hole
Reading the Childbirth Connection website got me interested in another question. Can c-sections prevent prolapse? Down a different rabbit hole I went. (This was a seriously obsessive way to use my kids’ nap times.)
As I said, the links on the Childbirth Connection website to the c-section versus vaginal birth systematic reviews weren’t working, so I had to go off on my own search.
From what I’ve read, women who have had c-sections (and no vaginal births) have lower rates of POP than women who have given birth vaginally. But, you’d need a lot of women having c-sections to stop one woman from suffering POP, so it’s not like women should go Brazilian style and have c-sections en masse.
For example, this study showed that “the prevalence of sPOP was doubled after vaginal delivery compared with caesarean section, two decades after one birth.” sPOP is short for “symptomatic pelvic organ prolapse.” And this study showed that c-section delivery has a protective effect similar to nulliparity.
The Argument that Childbirth is a Risk Factor for Pelvic Organ Prolapse
Based on the available research, I feel confident agreeing with the experts that vaginal childbirth is a risk factor for POP (I’m sure those experts are ecstatic an unknown blogger agrees with them).
Meredith, does that mean we are done and I can stop reading your post?
After reading the studies, two facts stuck with me.
- In the Johns Hopkins study called “Pelvic Floor Disorders 5–10 Years After Vaginal or Caesarean Birth”, the researchers found that, yes, vaginal birth is associated with more POP than caesarean birth is, but that the most dramatic risk was with “operative vaginal birth.” They also found that most women didn’t have POP. The takeaway: An operative vaginal birth is a red flag risk factor, not a vaginal birth per se. And if you give birth vaginally, you are more likely not to have POP than to have it. That’s good news. Not for me. But probably for you.
- Big babies and current high BMI increase your odds of POP. Perhaps this is obvious, but if you are blessed with big baby genes, this should be taken into consideration. And if you are overweight, yet another incentive to keep within a healthy range.
Some other studies look at older women and find that POP is nearly ubiquitous among them. Doesn’t this contradict what I just said about most women not getting POP? Life is confusing.
Anyway, I’m sure this is why some people say childbirth doesn’t cause POP. The argument goes “if most women don’t have POP after childbirth and most older women do have POP, something other than childbirth must be causing it.”
My answer to that: Good point. And yet, even assuming we can cross reference all these studies, just because POP has risk factors other than childbirth, doesn’t mean vaginal childbirth isn’t a big, or even the biggest, risk factor for some women (Even the studies that show late onset ubiquity note that higher vaginal parity and big babies increase the risk. Also, not all anatomical POP is symptomatic or gets worse with age).
We don’t know if the damage caused by childbirth is manifesting itself in the later years, so maybe childbirth was the main risk factor even for late appearing POP. Or maybe not. That’s the problem. We don’t know. What we do know is childbirth is a risk factor, not THE ONLY risk factor, but A COMPELLING RISK FACTOR.
Rates of POP are less important than symptoms. I’m not a scientist, but if I were, I’d suggest future studies focus more on symptomatic POP rather than on anatomical classifications of POP. This might help tease out some of the unanswered prevalence questions.
My Two Cents
If you already have POP, and you are done having kids, don’t succumb to childbirth regret. It’s over.
If you have POP and want to have more kids, talk to your doctor or midwife about your concerns.
If you don’t have POP and want to have kids, I would strive for a non-operative vaginal birth. BUT life happens. You can’t control everything about your life and your birth. Sometimes you need a c-section. Sometimes the baby gets stuck, cuts are made, fundal pressure is applied, pelvic floor structures are compromised. We move on.
Phew. Now I’m done. I’m climbing back up that rabbit hole so I can take care of my wonderful giant children.
Disclaimer: I disclaim a lot. I’m cautious. Remember, I’m not a medical professional, not even close. This post is for entertainment purposes (were you entertained?) and nothing more.