Brain lesions of fetal onset in encephalopathic infants with nonimmune hydrops fetalis.

Nonimmune hydrops fetalis (NIHF) comprised 79% (45/57) of all infants with hydrops fetalis at our institution over a 6-year period. Thirty-seven infants with NIHF were liveborn. One or more electroencephalograms were performed on 40% of liveborn infants (15/37); the majority (87%) were moderately to markedly abnormal, including burst suppression, lack of background, multifocal sharp waves, excessive discontinuity, and disorganization reflecting significant neonatal encephalopathies. Postmortem neuropathologic examinations were performed in 86% of infants with NIHF who died or were stillborn, 81% of whom demonstrated intrauterine brain insults including microcalcifications, cerebral and/or cerebellar hypoplasia, microcephaly, encephalomalacia, cavitary lesions, astrocytosis, polymicrogyria, and severe neuronal loss. Cranial ultrasonography failed to document the diverse pathologic lesions that were later noted on postmortem examination. Ten infants survived the neonatal period, but 6 were neurologically abnormal at the time of discharge. Infants with NIHF are at risk for antepartum brain injury, and electroencephalographic abnormalities reflect in part a fetal brain disorder. A prospective clinical study is needed to fully assess the prevalence, incidence, spectrum of central nervous system involvement, contribution of intrapartum and neonatal stress, and long-term outcome in surviving infants with NIHF.