Ask Busca: Breaking Water?

Elizabeth asked:

I have a question I'd love you to explore on your blog. In many of the birth stories I've read, Moms mention having their water deliberately broken by their midwife or doctor. Can this ever contradict a woman's internal timetable for the birth? Does water sometimes not break when it should, stalling labor? Is this practice ever considered an unnecessary intervention?

Busca's babble:

Artificial rupture of membranes (AROM, or amniotomy) is very common. Some care providers routinely break the bag of waters in an attempt to speed labor, especially in women who "fail" to follow the standard labor progress curve (at least one centimeter every hour). AROM is also used to induce labor, sometimes accompanied by prostaglandin gel and/or Pitocin. When an internal electronic fetal monitor is needed (to check baby's oxygen levels), AROM is performed to gain access to the fetal scalp. Sometimes AROM helps doctors or midwives determine whether a baby is in distress--as indicated by meconium in the amniotic fluid.

Can AROM ever contradict a woman's internal timetable for the birth? Certainly. Henci Goer, in her book The Thinking Woman's Guide to a Better Birth, explains, "[I]f left alone, two-thirds of laboring women reach full cervical dilation with membranes intact, and there are advantages to this" (p. 101). The amniotic sac and fluid serve a valuable purpose--not just during pregnancy, but during labor as well. Once a woman's bag of waters is ruptured, the chance of infection increases. Because of this, doctors and hospitals generally require that a woman with ruptured membranes give birth within 24 hours. (The chance of infection is much lower if vaginal exams are avoided.) So the membranes protect both mother and baby from infection. The fluid cushions the fetus and umbilical cord. Once the membranes rupture, the risks of cord compression and abnormal fetal heart rate patterns increase.

Early amniotomy also carries the frightening risk of umbilical cord prolapse. When a baby's head has not descended well into the pelvis, the gush of fluid can carry the umbilical cord into the vaginal canal where it will be compressed by the descending fetal head. This is an obstetric emergency requiring an immediate cesarean. My blogfriend, Sarah, recently shared her experience witnessing a doctor perform an unnecessary early amniotomy resulting in a cord prolapse and emergency cesarean. Oh that story made me seethe!

Does it hurt to leave the membranes intact? A recent Cochrane review of research assessing the use of AROM in spontaneous labors came to this conclusion:

Evidence does not support the routine breaking the waters for women in spontaneous labour. . . . Amniotomy has been standard practice in recent years in many countries around the world. In some centres it is advocated and performed routinely in all women, and in many centres it is used for women whose labours have become prolonged. However, there is little evidence that a shorter labour has benefits for the mother or the baby. There are a number of potential important but rare risks associated with amniotomy, including problems with the umbilical cord or the baby's heart rate. . . . The evidence showed no shortening of the length of first stage of labour and a possible increase in caesarean section. Routine amniotomy is not recommended for normally progressing labours or in labours which have become prolonged (Smyth RMD, Alldred SK, Markham C. Amniotomy for shortening spontaneous labour. Cochrane Database of Systematic Reviews 2007, Issue 4. Art. No.: CD006167. DOI: 10.1002/14651858.CD006167.pub2, emphasis added).

So, AROM carries known risks and apparently few benefits, at least when used routinely as it so often is.

When left alone, sometimes the amniotic sac never ruptures--births "in the caul." I sometimes wonder whether my second daughter would have been born in the caul since my sac remained intact until my CNM broke it at 9 centimeters. Navelgazing Midwife says this about AROM and births in the caul:

I'd heard about an OB that was so disgusted with AROM that he offered a $50 bounty for every caul birth and shelled out thousands before calling the game... proving that it is possible and isn't dangerous and not AROMing did not slow labors down, but, in fact, helped women cope better.

She also shares some of her fascinating experiences witnessing births in the caul. When handled correctly, there is no harm to being born in the caul. Navelgazing Midwife's conclusion? "I find, as time goes by, that I touch membranes less and less. I believe they are there for a reason... will break when ready... and serve a purpose we might never know" (source).

For two out of my three births, my membranes ruptured before the onset of labor. In the future, should my sac remain intact (as with my second birth), I think I'll request that it be left alone.