Clinical significance and outcome of preterm prelabor rupture of membranes: population-based study

Abstract

Objective: To evaluate maternal characteristics and neonatal and maternal birth outcome in cases of prelabor rupture of membranes (PPROM) in a non-selected parturient population.

Study design: The study population consisted of 5660 singleton preterm births (24-36 weeks gestation) occurring between 1988 and 1997 at the Soroka University Medical Center in Israel. Parturients with no prenatal care were excluded from the study. A cross-sectional study was designed between two groups. The study group consisted of patients with PPROM (n=968) and the comparison group consisted of patients without PPROM (n=4692). The data were analyzed by SPSS package. Information was obtained using a computerized database based on detailed obstetrical records. Logistic regression was used to assess the contribution of different risk factors to PPROM.

Results: PPROM was associated with a significantly lower gestational age (24-32 weeks) and birth weight (<2500 g) than those with intact membranes. The rates of chorioamnionitis and urinary infection were found significantly higher in the PPROM group compared with women without PPROM (16.5 vs. 2.7%; 5.1 vs. 3.3%, respectively) (P<0.001). The rate of endometritis and bacteremia in the postpartum period were significantly higher in women with PPROM compared with controls 2.8 vs. 1.4%, (P=0.003) and 9.4 vs. 5%, (P=0.001), respectively. Total perinatal mortality rates were significantly higher in the group without PPROM 10.5 vs. 7.2% (P=0.01), however, rates of postpartum death were higher in the PPROM group 5.5 vs. 4% (P<0.01). When adjusted for recognized risk factors using logistic regression analysis, infection of amniotic fluid (OR=6.6) and genito-urinary tract infection (OR=1.64) remained the independent risk factors associated with PPROM.

Conclusions: Infectious morbidity in patients with preterm prelabor rupture of membranes and preterm delivery remained an important risk factor for obstetrical and neonatal complications.