Clinical course of premature rupture of the membranes.

Premature rupture of the membranes (PROM), defined as rupture of the membranes before the onset of labor, is a common obstetric event occurring in 10% of pregnancies. Most of the time this occurs at or beyond 37 weeks' gestation with only 10% of PROM occurring at less than 37 weeks' gestation. The natural course of PROM is labor, and at term this is associated with a low rate of complications for the mother and the fetus. At less than 37 weeks' gestation PROM places the mother and the fetus at increased risk of short-term and long-term morbidity and mortality. Several factors related to preterm premature rupture of the membranes (PROM) add risk to the pregnancy and include premature delivery, infection in the mother and the fetus, effects of prolonged oligohydramnios on fetal development, abruptio placenta, prolapsed cord, and fetal malposition. Since the 1970s expectant management has been the standard treatment for PROM; however, in the majority of patients, this strategy results in the delivery of a preterm infant. In addition, controversy exists over the gestational age at which expectant management should be abandoned and active interventions to effect delivery pursued. This article discusses the natural history of PROM, the outcome of expectant management in PROM, and maternal and fetal outcomes in these patients. The emphasis of this discussion is on the preterm fetus.