Premature Rupture of Membranes at Term
I’ve been meaning to post this post for ages, but was never able to finish it during the school year last year. All of this comes from the research project that I worked on last year for 2 semesters as part of my research class, and even though I had to radically alter the goal and purpose of my research proposal in the end, along the way I had the opportunity to do some of the research I was really interested in doing in the first place, and it definitely needs to be shared. This is rather a long post, and it gets somewhat technical in places, but bear with me; a lot of the information here can help you fend off an unnecessary induction or cesarean, so it’s well worth reading. And with that, here we go:
Premature rupture of membranes (or prelabor rupture of membranes, aka PROM) occurs when a woman’s water breaks before she actually goes into active labor. It can happen to women at any point in their pregnancy, and when it happens to women who are still preterm, the danger to herself and her baby is much higher, as are the risks of infection (and many studies have demonstrated that in fact, preterm PROM, aka PPROM, is often caused by infection in the first place). However, the majority of PROM occurs in women who are at term gestation (37+ weeks)—90% of all cases, in fact (Zamzami, 2005), and it’s pretty common, too: PROM at term occurs in 8% of all births. (Hannah et. al., 1996)
In our hospitals today, there is sort of an unspoken rule—let’s call it the 24-Hour Rule. It goes something like this: if you haven’t delivered your baby within 24 hours of breaking your water, something is going to have to be done. In many cases, this something is induction, and in many cases, waiting a full 24 hours before inducing is something that never happens. Providers are often way too impatient and antsy for that, and will generally talk a woman into induction long before the 24 hours has passed. Many providers have the policy of immediately inducing a woman with PROM, either by using prostaglandin gels like cervadil followed by IV oxytocin (pitocin), or by just starting on the pit right away. The rationale for this type of management (often called active management) stems from research that was done in the 1960s (Shubeck, 1966; Rusell & Anderson, 1962) which found that the longer a woman was ruptured, the greater the chance of infection, chorioamnionitis (an acute infection of the chorion, which is part of the placenta), and maternal and/or fetal sepsis.
These early studies advocated immediate induction, and were the beginning of active management. The idea that the length of PROM is responsible for maternal infection is something which has sort of been hard-wired into modern obstetrical practice right now, and in my own experience, I have seen the 24-Hour Rule in effect many a time. Providers often use it to justify the need for an induction or augmentation, i.e. “we need to get your labor moving along, because you’ve been ruptured now for 8 hours…12 hours…18 hours…and you’re still not in active labor”, and as studies have shown, inductions and augmentations, especially for PROM, often lead to cesarean (Mozurkewich & Wolf, 1997; Grant et. al., 1992; Tan & Hannah, 2001). I have seen this deadline held over women’s heads before, and in my most humble opinion, it does absolutely NOTHING to help a woman relax, labor effectively, and have a vaginal delivery. (What’s that old Bradley joke about telling a man he better orgasm soon or else his penis will have to be cut apart to get to the sperm? No pressure, now!)
The thing is…the research from the ’60s, which forms the basis of the 24-Hour Rule, has more holes in it than swiss cheese. For one thing, these studies were retrospective, instead of prospective, which means that they relied on going back and looking at records after the births had already occurred, and never tried to control for any of the gazillion variables that might have affected these birth outcomes other than PROM. Similarly, these early studies were non-randomized, meaning that there might have been selection bias at play which could have muddied the findings. Additionally, both term and preterm pregnancies were mixed together when examining the effects of PROM, which seriously confounds results since preterm infants are much more susceptible to infection, and as I mentioned above, preterm PROM often occurs because of infection in the first place (McGregor & French, 1997). These studies had very imprecise definitions for infection, and the management protocols used were neither uniform or clearly discussed. And of course, NICUs and antibiotic therapy have improved so much in the past 40 years that many of the babies that died of infection in these early studies probably wouldn’t have died if they had been born today. So, as you can see, the studies from the 1960s had a lot of problems, and the fact that modern obstetrical practices are still based in part on the findings in these studies is an even BIGGER problem.
What have more recent studies shown? Well, many studies have shown that strict adherence to active management is often unnecessary, and in some cases, does more harm than good (seems to be a repeating theme when you start to look at obstetrical research—funny, that. And here is where it gets very technical. I’m putting the rest of this behind a cut, for those of you who are interested.)
