Hidden placental damage in stillbirths with idiopathic polyhydramnios.

Idiopathic polyhydramnios is clinically linked to stillbirth; however, its placental histopathology remains poorly characterized. This is the first study analyzing placentas from stillbirths with idiopathic polyhydramnios, revealing frequent lesions of fetal and maternal vascular malperfusion. Findings support a previously unrecognized role of placental dysfunction in fetal compromise.