Outcomes from polyhydramnios with normal ultrasound

OBJECTIVE: To investigate the short- and long-term outcomes of children from pregnancies complicated with polyhydramnios, defined as amniotic fluid index (AFI) >24 cm, and with a normal detailed ultrasound examination. METHODS: This retrospective cohort study examined 134 children aged 4 to 9 years with polyhydramnios and normal detailed ultrasound examination during pregnancy compared with 268 controls with normal AFI and normal detailed ultrasound examination matched for maternal age, year of delivery, gestational week at delivery, and presence or absence of diabetes. The primary outcome was the rate of malformations diagnosed postnatally. Additional outcomes were obstetrics outcomes, genetic syndromes, and neurodevelopment. RESULTS: Polyhydramnios was associated with increased risk for cesarean delivery (CD) and birth weight >90th percentile. This elevation in CD was attributed to increased rate of elective CD due to suspected macrosomia. Polyhydramnios was associated with increased risk for congenital malformations (n = 25 [19%] compared with 27 [10%], respectively; P = .016) without a statistically significant increase in the rate of major malformations (11 [8%] vs. 10 [4%]; P = .057). Genetic syndromes were more prevalent in the polyhydramnios group (5 [3.7%] vs. 2 [0.75%]; P = .043), as were neurologic disorders and developmental delay (9.7% vs. 3%; P = .004). CONCLUSIONS: Despite a normal detailed ultrasound examination, polyhydramnios is associated with increased rate of fetal malformations, genetic syndromes, neurologic disorders, and developmental delay, which may be diagnosed only after birth.