Preterm premature rupture of membranes: risks of recurrent complications in the next pregnancy among a population-based sample of gravid women.

OBJECTIVE: The purpose of this study was to ascertain the predictive value of antecedent preterm premature rupture of membranes for recurrent preterm premature rupture of membranes and preterm delivery rates in the next pregnancy compared with background rates among a population-based sample of women at a single institution. STUDY
DESIGN: Records of patients with index singleton pregnancies that were complicated by preterm premature rupture of membranes whose next delivery resulted in a delivery at >or=20 weeks at the same institution were reviewed for the incidence and gestational age of recurrent preterm premature rupture of membranes and preterm delivery. All subjects were patients of physicians whose obstetric practices were based at a single institution. Background rates of preterm premature rupture of membranes and preterm delivery in this population were generated from a systematically selected comparison group composed of the two deliveries after each of the study group's second delivery.
RESULTS: The rates of recurrent preterm premature rupture of membranes (16.7%) and preterm delivery (34.2%) in the 114 study group patients were substantially greater (odds ratio, 20.6; 95% CI, 4.7-90.2; and odds ratio, 3.6; 95% CI, 2.1-6.4) than noted background rates (0.96% and 12.5%) but considerably less than the recurrence rates of either preterm premature rupture of membranes or preterm delivery that were reported by others. The gestational age of preterm premature rupture of membranes in the index pregnancy affected neither the magnitude of risk nor the gestational age of recurrent preterm premature rupture of membranes or preterm delivery in the subsequent pregnancy. Stratification of outcome measures into three subgroups that were based on the gestational age of index preterm premature rupture of membranes demonstrated no significant differences in the incidence of preterm premature rupture of membranes or preterm delivery.
CONCLUSION: After a pregnancy that was complicated by preterm premature rupture of membranes, the risk for recurrent preterm premature rupture of membranes is increased by 20-fold and for recurrent preterm delivery by almost 4-fold. Gestational age of antecedent preterm premature rupture of membranes is predictive of neither risk nor timing of recurrent complications. Estimates of recurrence risks appear to be moderated by limiting analysis to a population-based sample of gravid women when compared with previous studies.