Premature rupture of the membranes and prolonged latency.

The aim of this retrospective study in 8320 patients with premature rupture of the membranes (PROM) was to determine the consequences of prolongation of the latent period. Among patients with pregnancies of more than 37 weeks' duration, those with PROM and latent periods of more than 1 day demonstrated an increased incidence of intrapartum fever (IPF), whereas those with latent periods of more than 3 days demonstrated a marked increase in fetal (but not neonatal) deaths. Although IPF and perinatal mortality were more common in preterm pregnancies, neither was found to increase or decrease with prolonged latency, provided differences in gestational ages and race were taken into account. In the absence of chorioamnionitis, there appears to be no benefit to delivery before 37 weeks' gestation.