The association between pregnancies complicated with isolated polyhydramnios or oligohydramnios and offspring long-term gastrointestinal morbidity.

Objective: Infants born to mothers with pregnancies complicated by polyhydramnios or oligohydramnios are at an increased risk for significant adverse perinatal outcome. We sought to assess whether in utero exposure to amniotic fluid abnormalities increases the risk of long-term gastrointestinal (GI) morbidity in the offspring.
Methods: In a population-based cohort study, the incidence of GI-related hospitalizations was compared between singletons exposed and unexposed to oligohydramnios or polyhydramnios. Deliveries occurred between the years 1991-2014 in a regional tertiary medical center. Offspring GI morbidity was assessed up to the age of 18 years according to a pre-defined set of International Classification of Diseases, ninth revision (ICD-9) codes associated with hospitalization. A Kaplan-Meier survival curve was used to compare cumulative morbidity incidence. A Cox proportional hazard model was performed to control for confounders.
Results: During the study period, 186,196 newborns met the inclusion criteria, of which 2.1% (n = 4063) and 3.0% (n = 5684) were born following pregnancies with oligohydramnios and polyhydramnios, respectively. The Kaplan-Meier curve demonstrated that children exposed to isolated oligohydramnios (but not to polyhydramnios) had higher cumulative incidence of GI morbidity (log-rank test, p = 0.001). In the Cox regression model, controlled for maternal age, gestational age, birth weight, and mode of delivery, isolated oligohydramnios (adjusted HR 1.2, 95% CI 1.04-1.34, p = 0.007), but not polyhydramnios (adjusted HR 1.1, 95% CI 0.91-1.13, p = 0.766), was found to be independently associated with long-term GI morbidity of the offspring.
Conclusion: In utero exposure to isolated oligohydramnios is an independent risk factor for long-term GI morbidity in the offspring.