To induce, or not to induce?

Typically, when a pregnant woman s water breaks prematurely, doctors will induce labor in order to avoid the increased risk of a uterine infection that could harm the fetus. Yet because there are also risks to delivering a baby pre-term, Dutch researchers have more closely investigated this practice. According to their study, induced labor is not necessarily a better option than watchful waiting.

The normal duration of a full-term pregnancy is 40 weeks. To examine the actual risk-benefit ratio of inducing labor in the case of premature rupture of the amniotic membranes at gestational age of 34 to 37 weeks, a team of researchers led by Dr. David van der Ham of the Masstricht University Medical Center studied 536 women whose water broke prematurely. They randomly assigned these women to either be induced or simply be monitored.

The Dutch researchers concluded that, in instances where a woman s water breaks at 34 to 37 weeks of gestation, inductions of labor do not substantially improve pregnancy outcomes. That is, among the newborns whose delivery was not induced, there was no higher rate of systemic infection or breathing problems. However, inducing labor was associated with a slight reduction in uterine or placental infection, known as chorioamnionitis.

Yet while this study, published in PLoS Medicine, has concluded that inducing labor should not necessarily be the standard response to pre-term membrane rupture, another expert in the field remains skeptical. Dr. Christian M. Pettker, a specialist in maternal fetal medicine at the Yale University School of Medicine, contends that the study wasn t large enough to establish definitively that waiting and monitoring doesn t, in fact, lead to an increased rate of major infections in newborns. As Dr. Pettker sees it, the higher rate of chorioamnionitis among deliveries that weren t induced suggests that, if there had there been more women included in the study, the researchers may have actually seen a higher rate of fetal blood infections.

ACSH s Dr. Gilbert Ross agrees with Dr. Pettker that, when a woman s water breaks at this later stage of gestation, deciding on a course of action should likely end up being a matter of discussion between the woman and her caregiver. Recent studies have shown that going into labor at 34 to 37 weeks may increase the incidence of adverse health outcomes for both the newborn and mother, suggesting that, absent any complications in the mother, delivery should be delayed until as close to 40 weeks as possible, he says. As Dr. Ross notes, more knowledge about the effects of waiting and watching is a good thing but the current study is truly too small to meaningfully determine whether fetal infection might still be more likely when labor is not induced.