Pregnancy outcomes after preterm premature rupture of membranes: The Japan Environment and Children's Study

To evaluate the pregnancy outcomes of preterm premature rupture of membranes (preterm PROM; PPROM) by gestational age.This cohort study analyzed data from the Japan Environment and Children's Study. Pregnancy outcomes were documented using descriptive statistics. Logistic regression was used to estimate the odds ratios (ORs) and 95% confidence intervals (CIs) of complications.Data were collected for 104 062 fetuses, and 99 776 were eligible for inclusion. The incidences of early (18-23 weeks) and late (24-36 weeks) PPROM were 0.1% (n = 102) and 1.2% (n = 1205), respectively. Of the 1307 cases, 66 (5.0%) resulted in miscarriage or stillbirth. Overall, 85.6% (1119/1307) resulted in preterm births, and 9.3% (122/1307) in term births. There was a higher incidence of oligohydramnios (OR 6.82, 95% CI 4.07, 11.4; OR 2.42, 95% CI 1.72, 3.40), intrauterine infection (OR 11.9, 95% CI 7.06, 19.9; OR 4.39, 95% CI 3.01, 6.41), cesarean delivery (OR 3.31, 95% CI 2.32, 4.71; OR 1.34, 95% CI 0.97, 1.85), placental abruption (OR 5.57, 95% CI 2.30, 13.5; OR 5.40, 95% CI 3.58, 8.14), and 5-min Apgar score <7 (OR 35.3, 95% CI 21.5, 57.9; OR 2.66, 95% CI 1.75, 4.05) for early and late, compared to no, PPROM, respectively. Miscarriage or stillbirth was higher in early (OR 5.84, 95% CI 3.72, 9.15) and lower in late (OR 0.21, 95% CI 0.06, 0.68) compared to those without PPROM.This study described the epidemiology of pregnancy outcomes of early (occurring at the limit of viability) and late PPROM.