About 11% of women who carry to term will experience prelabor rupture of membrane—a condition where the amniotic sac breaks open early, but labor doesn’t begin.

Typically, when a woman’s water breaks but labor doesn’t start, labor is induced. But a new University of Michigan study found that expectant management––waiting a period of time after the water breaks for labor to begin spontaneously––did not significantly increase risk to the fetus or the mother in healthy pregnancies.

Therefore, both induction and expectant management should be considered, and the decision should be made in the context of the mother’s wishes and health, said study co-author Ruth Zielinski, a nurse midwife and U-M clinical professor in nursing.

The American College of Obstetricians and Gynecologists recommends induction, but in healthy pregnancies carried to term the American College of Nurse Midwives recommends expectant management be offered as an option.

During pregnancy, the fetus is surrounded by a fluid-filled membrane called the amniotic sac. At some point at the beginning of or during labor, this sac ruptures and contractions typically begin soon after. The goal of the study was to examine rates of induction, maternal infection, neonatal outcomes and time to birth in women who carried to term, and were expectantly managed at home or in the hospital.

Zielinski and colleagues looked at 2,357 women cared for by a midwestern midwifery service between January 2016 and December 2018. The amniotic sac ruptured early in 281 women (12%). Among that group, 150 (53%) opted to wait for labor onset at home; 102 (36%) were expectantly managed in the hospital; 21 (7.5%) were admitted for immediate induction of labor; and 8 (3%) were admitted for immediate cesarean birth.

Of the women who opted to wait, the majority (65%) went into labor on their own and did not need to be induced. Rates of maternal and infant infection were no different between the groups of women with prelabor rupture of membranes.

Labor is typically induced when the water breaks early because the prevailing wisdom is that as the time between the amniotic sac rupturing and the beginning of labor grows, so does the risk of infection.

“The risk of infection does increase with prolonged ruptured membranes, which is why with prelabor rupture of membranes, when the mother is a Group B strep carrier, the recommendation is a shorter duration of expectant management,” Zielinski said.

Group B strep is a common bacteria that does not cause maternal infections, and providing antibiotic prophylaxis during labor is recommended to decrease the risk of transmission to the newborn.

The majority of newborns will not get sick but if they do, they get quite sick, which is why antibiotics are recommended, Zielinski said.

“Twenty-six years ago when I graduated from midwifery school, I assumed everyone wanted to avoid induction, but this is definitely not the case,” she said. “Often, patients want to get things going and are fine with induction. However, with healthy, term pregnancies, waiting for a period of time for labor to start is reasonable and should be offered.”

It is important for women to discuss their options with their provider, she said.

More information:

• Study abstract: Outcomes of Expectant Management of Term Prelabor Rupture of Membranes
• Ruth Zielinski