Risk Factors for Neonatal Bronchopulmonary Dysplasia in Extremely Preterm Premature Rupture of Membranes: A Retrospective Study
Abstract Background:Determination of the optimal timing for termination of pregnancy in cases of preterm premature rupture of membranes (pPROM) during the extremely preterm period is still difficult. Bronchopulmonary dysplasia (BPD) is a major disease widely taken into account when determining the prognosis of respiratory disorders in a neonate. Many aspects of this disease remain unclear. With the aim of further improving the prognosis of neonates born to mothers with pPROM, this study examined cases who were diagnosed with pPROM before 28 weeks of gestation. The study analysed risk factors for neonatal BPD and the optimal timing for termination of pregnancy in pPROM cases.Methods:Subjects were 73 cases of single pregnancy who were diagnosed with pPROM during the period from 22 weeks and 0 days to 27 weeks and 6 days of gestation. The following factors were retrospectively examined: the gestational week at which a diagnosis of pPROM was made; the gestational week at which delivery occurred; the period for which the volume of amniotic fluid was maintained; and neonatal BPD as a complication. A receiver operating characteristic (ROC) curve was drawn in order to analyse the relationship between the duration of oligohydramnios and the onset of BPD.ResultsThe mean gestational week at which a diagnosis of amniorrhexis was made was 24.5 ± 1.9 weeks (mean ± SD), and that at which delivery occurred was 27.0 ± 3.0 weeks. Fifty-seven cases (78.1%) were diagnosed with oligohydramnios, the mean duration of which was 17.4 ± 20.5 days. The mean birth weight of neonates was 1000 ± 455 g, of which 49 (67.1%) were diagnosed with BPD following birth. No neonates died in this study. Multivariate analysis of various risk factors for the onset of BPD indicated that oligohydramnios is an independent risk factor for BPD. The ROC curve indicated that the cut-off value was 4 days. In this case, the levels of sensitivity and specificity for predicting the onset of neonatal BPD were 0.941 and 0.917 respectively.ConclusionOur findings suggest that oligohydramnios is an independent risk factor for BPD in cases who are diagnosed with pPROM before 28 weeks of gestation.