Third trimester preterm and term premature rupture of membranes: Is there any difference in maternal characteristics and pregnancy outcomes?

The clinical significance and management of preterm premature rupture of membranes (PPROM) remains a topic of a controversy. Although PROM is associated with a low rate of complications, PPROM may lead to significant neonatal and maternal morbidity.

We performed a retrospective study of 714 women who presented to Jiangsu Province Hospital with third trimester PPROM or PROM between January and December 2015. The data were analyzed by SPSS; the significance of maternal characteristics, and maternal and neonatal outcomes were tested using Student's t test and the χ² test. A two-sided p value < 0.05 was considered statistically significant.

There were 714 women included in this analysis. We identified 577 (80.8%) women with PROM and 137 (19.2%) with PPROM. In the PPROM group, we further divided the women into 28⁺⁰-31⁺⁶ weeks (n = 21) and 32⁺⁰-36⁺⁶ weeks (n = 116) of gestational age. PPROM was associated with a significantly lower gestational age, and patients in this group showed higher C-reactive protein and body temperature when admitted to the hospital (p < 0.05). Breech presentation and history of previous cesarean section were associated with occurrence of PPROM compared with PROM (p < 0.05). The PPROM group showed a significantly longer latency period compared with the PROM group, in which the latency period increased with the lower gestational age (28⁺⁰-31⁺⁶ weeks). Significantly higher neonatal intensive care unit (NICU) admission rate was shown in the PPROM group as compared with the PROM group, and gestational age 28⁺⁰-31⁺⁶ weeks yielded a significantly higher rate of NICU admission than 32⁺⁰-36⁺⁶ weeks did (p < 0.05).

Higher C-reactive protein and body temperature in the PPROM group suggest an asymptomatic infection that requires close monitoring to prevent any adverse effect on pregnancy outcome. Longer latency period in PPROM group is predictable in order to minimize perinatal morbidity and mortality because of prematurity itself. Therefore, an increase in gestational age plays an important role that can affect a clinician's decision making regarding whether to transfer to the NICU.