Preterm premature rupture of membranes: comparison between twin and singleton gestations

The purpose of this study was to evaluate the clinical characteristics and pregnancy outcomes of twin and singleton pregnancies complicated by preterm premature rupture of membranes (PROM) and to compare the groups to evaluate for differences in these areas. In this retrospective study, patients with a gestational age of < 36 weeks admitted between 1993 and 1996 with PROM were evaluated for their clinical characteristics and pregnancy outcomes. Twin and singleton pregnancies were compared and the results were evaluated for significant differences. Patients with lethal fetal anomalies, clinical chorioamnionitis at presentation, or fetal distress at presentation were excluded from analysis. Liberal use of tocolysis was provided to both groups of patients, as were serial doses of betamethasone and vitamin K. Twenty-eight sets of twins and 119 singleton pregnancies were included in the analysis. Differences were noted with respect to twin and singleton pregnancies for both latency period (4.26 days vs 8.6 days, P < 0.001) and birthweight (1,464 vs 1,698 g, P < 0.03). The birthweight for twins was an average of the pair. No differences were noted with respect to gestational age at time of rupture, maternal age, gravidity, parity, race, tocolytic use, steroid use, prophylactic antibiotics, or sexually transmitted diseases. The incidence of chorioamnionitis showed a trend for a higher occurrence in singleton pregnancies. The latency period for twin pregnancies complicated by preterm PROM is shorter than for singleton pregnancies. The incidence of chorioamnionitis may be higher in singleton pregnancies, but this may be related to their longer latency period. A knowledge of these differences may be of benefit when counseling these patients.