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

PURPOSE: To identify risk factors and perinatal outcomes associated with the duration of latency period in women who experience preterm premature rupture of membranes (PPROM).

METHODS: A retrospective study of women who experienced PPROM between 24 and 34 weeks 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 ≤72 h and Group 2 >72 h. 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.

RESULTS: 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).

CONCLUSION: Gestational age at PPROM, twin gestation, and oligohydramnios significantly affected the latency period. Although a latency period >72 h was associated with chorioamnionitis and placental abruption, adverse neonatal outcomes were not affected.