Prognosis of preterm premature rupture of membranes between 20 and 24 weeks of gestation: A retrospective cohort study

BACKGROUND: The previous study on prognosis of preterm premature rupture of fetal membranes (pPROM) near the limit of viability showed various survival rate raging from 26 to 57 %%. This may be partly due to the fact that treatment of prematurely born babies vary from one country to another, or sometimes within a single country. In Japan, resuscitation efforts are made to newborns of early gestational age, normally from 22 weeks of gestation. OBJECTIVE: To assess the natural history and short- and long-term prognosis in pregnancies complicated by preterm premature rupture of membranes (pPROM) near the limit of viability in a hospital in Japan. METHOD: We conducted a single-center retrospective cohort study. Cases with diagnosis of pPROM at a gestational age of 20–23 6/7 weeks and delivered in our hospital between April 2007 and December 2017 were examined. RESULT: 66 cases were included and of those, 54 (81.1 %) newborns survived to discharge. Of the neonates who survived to discharge, 42 (77.8 % of survivors) experienced severe morbidity at the time of discharge. Multivariate logistic regression analysis showed that later gestational age at pPROM and longer latency period were significantly associated with survival with no severe morbidities (per one day increase, adjusted odds ratio (OR) 1.37, 95 % CI 1.03–1.83, p = 0.033 and per one day increase, adjusted OR 1.11, 95 % CI 1.02–1.21, p = 0.015). Of 23 cases followed at 36 months, 8 (34.8 %) showed developmental delay. CONCLUSION: The survival rate was significantly higher than the previous studies, yet many of the survivors experienced short-term severe morbidity. Of those who experienced short-term severe morbidity, however, more than half showed normal range development at 36 months.