Risk factors and perinatal outcomes associated with latency in preterm premature rupture of membranes between 24 and 34 weeks of gestation

Abstract

To identify risk factors and perinatal outcomes associated with the duration of latency period in women who experience preterm premature rupture of membranes (PPROM). A retrospective study of women who experienced PPROM between 24 and 34weeks of gestation was performed in a single tertiary center between 2009 and 2013. Patients were divided into two groups based on the duration of the latency period after PPROM: Group 1 ≤72h and Group 2 >72h. Risk factors and perinatal outcomes were compared according to latency period. Student's t test and Chi-square test were used to compare continuous and categorical variables, respectively, between the two groups. Multivariate regression analysis was performed to control for potential confounding variables. In total, 3,257 patients presented with PPROM during the study period; of these, 204 (6.3%) met the inclusion criteria. Higher gestational age upon admission (odds ratio [OR]=0.83, 95% confidence interval [CI]=0.79-0.87; p<0.001), oligohydramnios (OR=0.47, 95% CI=0.25-0.91; p=0.018), and twin gestation (OR=0.67, 95% CI=0.45-0.89; p=0.032) were independently associated with a shortened latency period. In addition, prolonged latency significantly increased the occurrence of chorioamnionitis (OR=2.23, 95% CI=1.48-3.14; p=0.002), placental abruption (OR=1.9, 95% CI=0.95-3.53; p=0.033), and decreased the length of stay of neonates in the intensive care unit (OR=0.85, 95% CI=0.39-1.79; p=0.021). Gestational age at PPROM, twin gestation, and oligohydramnios significantly affected the latency period. Although a latency period >72h was associated with chorioamnionitis and placental abruption, adverse neonatal outcomes were not affected.