What to expect after birth in idiopathic polyhydramnios? An analysis of postnatal diagnoses and their relationship to the polyhydramnios degree.

Purpose: To analyze postnatal abnormalities in idiopathic polyhydramnios and to estimate whether there was an association between the severity of polyhydramnios and postnatally diagnosed abnormalities. Methods: This was a retrospective cohort study of all idiopathic polyhydramnios cases delivered at our center between 2017 and 2021. Cases were identified as idiopathic after excluding known fetal genetic or structural abnormalities (including soft markers for aneuploidies), Rh isoimmunization, fetal anemia, multifetal pregnancies, pregestational or gestational diabetes, and known infection with TORCH group agents. The primary outcome was the association between polyhydramnios degree and any abnormalities detected after birth. Additional outcomes were the odds of specific groups of abnormalities based on polyhydramnios degree. Results: The prevalence of idiopathic polyhydramnios was 14.7%. Outcomes of 242 pregnancies with idiopathic polyhydramnios were analyzed. At least one neurodevelopmental, structural, or genetic abnormality was diagnosed in 16.1% of children born to women with idiopathic polyhydramnios. Moderate and severe polyhydramnios are significantly associated with at least one abnormality diagnosed after birth (45.9%, and 41.6%, respectively, p < 0.05). Neurodevelopmental disorders were the most frequent abnormality (5.4%), followed by genetic abnormalities (4.1%) and gastrointestinal abnormalities (2%). Odds of genetic abnormalities and neurodevelopmental disorders in moderate polyhydramnios were significantly higher compared to mild [OR 2.6; 95% CI 1.1–4.3 and aOR 2.4 (95% CI 1.1–3.6) respectively]. As expected, gastrointestinal anomalies were significantly associated with severe polyhydramnios [OR 3.2 (95% CI 1.9–5.5)]. Conclusion: Moderate and severe idiopathic polyhydramnios are associated with anomalies diagnosed after birth. Particularly high risks include neurodevelopmental disorders, genetic abnormalities, and gastrointestinal atresias. [ABSTRACT FROM AUTHOR]