Intrauterine positional deformations masquerading as multiple congenital malformations.

A 1,340-g male neonate was delivered by emergency cesarean section at 28 weeks' gestation following failed therapy with isoxsuprine hydrochloride and fetal distress. Transverse-lie presentation with the posterior side of the thorax wedged into the maternal pelvis and the head flexed firmly against the anterior side of the thorax led to a severe deformation sequence initially interpreted as multiple congenital malformations. This case illustrates the difficulty in distinguishing between pure deformations and malformations with and without subsequent deformations. It also emphasizes the clinician's need for a definitive diagnosis to guide the management of suspected malformations that are potentially lethal or portend a poor neurodevelopmental outcome.