Identifying risk factors for premature rupture of membranes in small for gestational age neonates: a population-based study

Objective. To determine the prevalence and risk factors for premature rupture of membranes (PROM) among pregnancies complicated with small for gestational age (SGA) neonates.

Methods. A computerised database was used to identify deliveries of SGA neonates in pregnancies complicated with PROM between the years 1988 and 2002. Pregnancies with PROM and SGA neonates were compared to those with SGA and without PROM. Demographic, obstetric, clinical and labour characteristics were evaluated. Multiple logistic regression analysis was used to determine independent risk factors for PROM in pregnancies complicated by SGA. Statistical analysis was performed with SPSS package.

Results. There were 120 982 deliveries included out of which 6074 (5.99%) presented with appropriate for gestational age (AGA) neonates and PROM. A total of 1077 delivered SGA infants complicated with PROM (5.5%). After adjustment for confounding variables, the following characteristics were significantly associated with PROM and SGA: Jewish ethnicity, parity and cervical incompetence. The following complications were associated with PROM and SGA: arrest of labour, fetal distress, failed induction, cesarean delivery, clinical chorioamnionitis and placenta accreta. No significant differences regarding low Apgar scores and perinatal mortality rates were noted.

Conclusions. The risk of PROM among patients with SGA is lower than in AGA infants. Parity and cervical incompetence are risk factors for PROM among women who delivered SGA neonates. In this population there is a higher rate of arrest of labour, chorioamnionitis, fetal distress and cesarean delivery. Neonatal outcome and perinatal mortality are similar in both groups.