Premature contraction of the ductus arteriosus: a cause of foetal death.

Necropsy findings are presented of two cases of foetal heart failure secondary to premature, in-utero contraction should lead to a redirection of the right heart output either through the pulmonary vascular bed or to the systemic circulation via the foramen ovale. The muscular pulmonary arteries, however, were not dilated, indicating that no excessive pulmonary flow had occurred. The increased volume load on the right heart may have rendered the foramen ovale restrictive, with right-sided heart failures as a consequence. Premature closure of the ductus arteriosus should be considered a cause of foetal or early neonatal death.