Prolonged oligohydramnios and the adverse composite outcome of death or severe neurodevelopmental impairment at 3 years of age in infants born at 22-29 gestational weeks.

OBJECTIVE: To investigate the association between prolonged oligohydramnios and a composite outcome of death or severe neurodevelopmental impairment (NDI) at 3 years of age.

METHODS: This single-center retrospective cohort study enrolled infants born at 22-29 weeks of gestational age without major congenital anomalies. The patients were classified into three groups depending on the existence and duration of oligohydramnios: no/non-prolonged oligohydramnios (no or 0-7 days of oligohydramnios), prolonged oligohydramnios (8-14 days), and very prolonged oligohydramnios (> 14 days). The primary outcome was a composite of death or severe NDI, which was defined as severe cerebral palsy, developmental delay, severe visual impairment, or deafness at age 3.

RESULTS: Out of the 843 patients, 784 (93 %), 30 (3.6 %), and 29 (3.4 %) were classified into the no/non-prolonged, prolonged, and very prolonged oligohydramnios groups, respectively. After excluding patients lost to follow-up, the adverse composite outcome at 3 years of age was observed in 194/662 (29 %), 7/26 (27 %), and 8/23 (35 %) in the corresponding groups. The composite outcome showed no significant trend with the duration of oligohydramnios (P = 0.70). In a logistic regression model controlling the known predictors of gestational age, birth weight, small-for-gestational-age, male sex, multiple pregnancy, hypertensive disorders of pregnancy, antenatal corticosteroids, and the number of family-social risk factors, the duration of oligohydramnios was not independently associated with the composite outcome; odds ratio 1.3 (95 % confidence interval, 0.78-2.0).

CONCLUSION: Prolonged oligohydramnios was not associated with the composite outcome of death or severe NDI at 3 years of age.