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

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

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.

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.

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