Neonatal Outcomes are Similar between Patients with Resolved and Those with Persistent Oligohydramnios

ObjectiveOligohydramnios (defined as amnioticfluid volume<5cm or deepestvertical pocket<2cm) is regarded as an ominousfinding on prenatal ultrasound.Amnioticfluid, however, is not static, and to date, there have been no studiescomparing perinatal outcomes in patients who are diagnosed with oligohydramniosthat resolves and those who have persistent oligohydramnios.Study DesignThis is a secondary analysis of a National Institutes of Health-fundedretrospective cohort study of singleton gestations delivered at a tertiary care hospitalbetween 2002 and 2013 with mild hypertensive disorders and/or fetal growthrestriction (FGR). Maternal characteristics, delivery, and neonatal information were abstracted by trained research nurses. Patients with a diagnosis of oligohydramnioswere identified, and those with resolved versus persistent oligohydramnios at the timeof delivery were compared. The primary outcome was a composite of neonatalresuscitation at delivery: administration of oxygen, bag-mask ventilation, continuouspositive airway pressure, intubation, chest compression, or cardiac medication admin-istration. Secondary outcomes included FGR, timing, and mode of delivery.Results Of 527 women meeting study criteria, 42had oligohydramnios that resolvedprior to delivery, whereas 485 had persistent oligohydramnios. There were nosignificant differences in patient demographics between groups. The gestationalage at diagnosis was significantly lower for patients with resolved versus persistentoligohydramnios (median: 33.0 [interquartile range, IQR: 29.1-35.9] vs. 38.0 [IQR 36.4-39.3],p<0.001). There was not a substantial difference in rate of neonatalresuscitation (41 vs. 32%,p<1/4>0.31). Patients with resolved oligohydramnios were more likely to have developed FGR than those with persistent oligohydramnios (55 vs. 36%,p<0.02). There were no significant differences for gestational age at delivery, birthweight, or neonatal intensive care unit admission.ConclusionPatients whose oligohydramnios resolved were diagnosed earlier yet hadsimilar rates of neonatal resuscitation but higher rates of FGR than those who hadpersistent oligohydramnios.