Continuous fetal head flexion as a marker for prenatal diagnosis of lethal multiple pterygium syndrome: a case report

Lethal multiple pterygium syndrome (LMPS) is a fatal hereditary disease associated with abnormalities such as pterygium-induced congenital contractures. Fetal hydrops is present in more than half of all patients with LMPS, and all patients with LMPS are either stillborn or die in the early neonatal period. Ultrasonography findings for the prenatal diagnosis of LMPS include the detection of cutaneous webbing at multiple joints, multiple joint contractures, absent limb movement, and increased nuchal translucency. Here, we describe a patient who was diagnosed as having LMPS due to continuous fetal head flexion, despite the absence of the usual characteristics of the condition, including pterygium at the joints. Thus, continuous fetal head flexion can be a useful marker for prenatally diagnosing LMPS.