Pregnant women whose waters break late in preterm pregnancy but before they are in labor - the medical term for this situation is preterm prelabor rupture of the membranes - are best managed by monitoring and waiting until they deliver spontaneously rather than by inducing labor according to a study by Dutch researchers published in this week's PLoS Medicine.

In their study, David van der Ham, from the Maastricht University Medical Center, Netherlands, and colleagues randomized over 500 pregnant women with preterm prelabor rupture of the membranes between 34-37 weeks gestation to receive either immediate induction of labor or expectant management (monitoring and waiting).

The authors found that there were no real (statistically significant) difference in the number of babies who had a blood infection (neonatal sepsis) or who developed lung difficulties (respiratory distress syndrome) between the two groups. Furthermore, the researchers also found that Cesarean section rates were similar in both groups but that the risk of maternal infection (chorioamnionitis) was slightly reduced in the induction of labor group compared to the expectant management group. These results were consistent with an updated analysis of all relevant studies (meta-analysis), which the authors performed.

The authors say: "We conclude that in pregnancies complicated by [preterm prelabor rupture of the membranes] between 34 and 37 wk of gestation the incidence of neonatal sepsis is low. Neither our trial nor the updated meta-analysis shows that [induction of labor] substantially improves pregnancy outcomes compared with [expectant management]."

The authors continue: "Despite some differences in baseline characteristics, we assume that the results of our study can be generalized to at least the Dutch/Western European population."

However, they add: "Because of wide differences in general health care and availability of antibiotics, it is likely that these results cannot be generalized to low-income countries."