ABSTRACT
Prelabor rupture of the membranes (PROM) is rupture of the chorioamniotic membranes before the onset of labor. In addition, the authors reported that histologic chorioamnionitis in PROM was twoto threefold more common when rupture of membranes occurred just before the onset of labor than when it occurred after labor began. An alternative hypothesis to explain the relationship between abruptio placentae and preterm PROM postulates that a disorder of decidual hemostasis leads to separation of the membranes from the decidua, with subsequent compromise of their nutritive support, weakening of the membranes, and eventual rupture. The risk of pulmonary hypoplasia when PROM occurs at 19 weeks was 50%, whereas it was only 10% when the membranes ruptured at 25 weeks. Univariate analysis demonstrated an association between the duration of rupture of membranes and the occurrence of pulmonary hypoplasia. The site of rupture is generally located in the most dependent part of the uterine cavity in close proximity to the cervix.
