Belly Up

* bellies * birth * babies * breastfeeding *

Tuesday, October 4, 2011

PROM-Not About Big Hair and Fancy Dresses

Not that kind of prom!
It seems on TV that every pregnant character has a scene when out of the blue her water breaks and intense contractions immediately follow.  However, while a big gush of water makes for good television, labor starting in this fashion is the exception and not the rule.  Left to its own devices, most of the time the bag of waters (BOW) will  rupture during transition, that crazy intense time at the end of labor and not at the beginning of the process.  When labor starts with the water breaking,  that is called PROM, or premature/prolonged rupture of membranes. 

Here are the cliff notes for PROM as it pertains to full-term labors:
  • PROM is defined as the BOW breaking 1 hour prior to the start of contractions
  •  PROM is thought to affect 8-10% of all pregnancies
  •  75% of women will spontaneously start labor within 24 hours after PROM
  •  95% of of women with PROM will deliver within 28 hours
While PROM may be a normal variation of labor, the small (but normal) percentage of moms that experience PROM do face special challenges, especially if they are hoping for a low intervention birth.  The standard of care that most OBs practice is that when a mom's water breaks she is directed to come into the hospital post haste regardless if she is having contractions or not.  If she is not having contractions, she may be given a bit of time to walk around to see if labor starts, but most likely she will be encouraged to start a chemical induction and told that choosing to delay this induction will increase the risk of infection to herself and her child.

As noted, statistics do show that labor will likely start one way or the other within 24 hours, which means some women will start having regular contractions immediately while others will start at hour 23.  The problem is no one knows which women will be the fast starters and who will be just getting going in the 23rd hour.  In light of that range of variation, the differences in the managed care model of chemical induction and the watchful waiting model of the expectant care can be discussed. 
There is a lot of research on PROM and as usual it is not a black and white issue.  It is clear in the studies that most moms will shortly start labor on their own (within 24 hours) and various studies have compared the risk of infection between the watchful waiting approach vs the do something now approach.  Most research states that there is little statistical difference in neonatal  infection rates between the two groups, though there may be a slight increase in the risk of maternal infection in the expectant group.  Infection rates in either group though are both low, under 1%.  (Ironically one study states that despite infection rates being equal, more babies are actually sent to the NICU for observation after the expectant approach which probably indicates a bias assuming expectant care will lead to problems despite there being proof to the contrary)*  C-section rates have also been compared and rates are found to be comparable in both groups of women.

Amniosure, a test to
 confirm rupture of membranes
 However, muddying the waters (love a good pun!) is that while most studies do indicate that the risk of maternal infection rises slightly around 24 hours post water breaking, there is evidence that suggests the risk may actually rise 24 hours after the first vaginal exam not just from the time of the rupture.  To put that in perspective, what happens when mom goes into the hospital (as directed) right after her water breaks?  Mom gets a vaginal exam to determine if her water really broke and to asses what is happening with her labor. Since the time of her water breaking and the time of her first exam will then correspond fairly closely, it is hard to definitively say if the infection risk goes up due to the water being broken or if it is increased due to the vaginal exams...or perhaps some combo of the two.

What does this mean for expecting couples?  If your water breaks what should you do?  These are great questions and expectant parents should preferably decide how they want to answer them before finding themselves leaking amniotic fluid.  The answer will depend on the careprovider, the couple's attitude toward the research, the type of birth they are planning and even the ever present concern about rush hour traffic.  If one experiences PROM and the decision is made to hang out at home, mom should eat/drink and try to get some rest.  She can pay attention to her baby's movements, be aware if she starts to run a fever and follow her intuition.  If it is chosen to go into the hospital mom should limit vaginal exams and discuss with her careproviders the risks of using pitocin to start labor vs the risks of waiting for labor to start.  She can also consider low tech ways of bringing on labor such as nipple stimulation with a breast pump or walking.

*Abstract of this particular study: