Etiology and perinatal outcome of polyhydramnios.

PURPOSE: To determine causes of polyhydramnios and the respective perinatal outcome.

MATERIALS AND METHODS: We retrospectively analyzed cases with polyhydramnios at the Medical University Graz, Austria from 2003 - 2011. Inclusion criteria were single deepest pocket ≥ 8  cm, amniotic fluid index ≥ 25  cm, each of the latter parameters > 95th percentile or subjective impression. Etiologies, including TORCH infection, diabetes and congenital malformations, as well as perinatal outcome were evaluated.

RESULTS: Out of 860 singleton pregnancies with polyhydramnios, 2.9 % had positive TORCH serology, 8.5 % had congenital anomalies, 19.8 % had maternal diabetes, and 68.8 % were idiopathic. The most common fetal anomalies were cardiac defects (32.9 %). Elective caesarean sections were more common in the groups with malformations and maternal diabetes. Low birth weight combined with severe polyhydramnios or maternal diabetes was associated with malformations.

CONCLUSION: Diagnosis of polyhydramnios should prompt glucose-tolerance testing, detailed sonography including fetal echocardiography, and TORCH serology. Especially pregnancies with polyhydramnios and small fetuses as well as those with maternal diabetes should be carefully evaluated for malformations.