Targeted delivery at 34 versus 35 weeks in women with preterm prelabor rupture of membranes

Objective: To compare planned delivery at 34 versus 35 weeks for women with preterm prelabor rupture of membranes (PPROM). Materials and methods: We performed a retrospective cohort study of singleton pregnancies with PPROM after 24 weeks delivered from 2006 to 2014. In 2009, an institutional practice change established 35 weeks as the target gestational age before induction of labor was initiated after PPROM. Demographic and outcome measures were compared for two cohorts: women delivered 2006-2008 - target 34 weeks (T34) and women delivered 2009-2014 - target 35 weeks (T35). The primary outcome was neonatal intensive care unit (NICU) admission. Results: Of the 382 women with PPROM, 153 (40%) comprized the T34 cohort and 229 (60%) comprized the T35 cohort. Demographic characteristics were similar between groups. There were no differences between groups in gestational age at PPROM (31.0 ± 3.3 weeks versus 31.2 ± 3.1 weeks; p = .50) or maternal complications. The mean gestational age at delivery was earlier in the T34 group (31.8 ± 3.2 weeks versus 32.4 ± 2.7 weeks; p = .04). The median predelivery maternal length of stay (LOS) was 1 day longer in the T35 group (p = .03); the total and postpartum LOS were similar between groups (p > .05). There were no differences in the rate of NICU admission (T34 89.5% versus T35 92.1%; p = .38) or median neonatal LOS (T34 14 days versus T35 17 days; p = .15). In those patients who reached their target gestational age, both maternal predelivery LOS and total LOS were longer in the T35 group (p > .05). The frequency of NICU admission in those reaching their target gestational age was similar between groups (T34 83.37% versus T35 76.19%; p = .46). Conclusions: A 35-week target for delivery timing for women with PPROM does not decrease NICU admissions or neonatal LOS. This institutional change increased maternal predelivery LOS, but did not increase maternal or neonatal complications.