[Postnatal outcome from polyhydramnios without sonographic abnormalities]

To assess adverse outcome of polyhydramnios without morphological abnormalities and to determine the factors associated with an adverse outcome.

This is a retrospective observational cohort study conducted in a French tertiary care unit between 2008 and 2018 including all women with singleton pregnancy complicated by polyhydramnios. Presence of morphological abnormality was an exclusion criteria. The primary outcome was the rate of adverse outcome, defined by a composite criterion including death or postnatal discovery of malformation or chronic pathology. Maternal, obstetrical, paediatric and polyhydramnios characteristics were collected.

Ninety-one women with polyhydramnios were included. The rate of adverse outcome was 24.2% (22/91). This rate was 20,3% in case of idiopathic polyhydramnios and 33,3% in case of maternal diabetes associated. The postnatal mortality rate was 5.5%. The rate of malformations not diagnosed in antenatal was 11%. Obesity (50% vs. 18,8%; P=0,004), early diagnosis (72,7% before 32 WG vs. 44,9%; P=0,02), and severity of polyhydramnios (22,7% vs. 4,3% in severe polyhydramnios; P=0,01) were associated significantly with an adverse outcome. In these cases, the incidence of preterm delivery was higher.

Polyhydramnios must have second-line ultrasound, including isolated maternal diabetes. A systematic genetic assessment can be discussed.