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Nonimmune hydrops fetalis associated with genetic abnormalities.

The purpose of this review of the literature on nonimmune hydrops fetalis was to evaluate whether recent clinicopathologic studies have modified the relative incidence of the different associated conditions and the management of these pregnancies. We found 600 cases of nonimmune hydrops fetalis published since 1982. These cases were reviewed with particular attention to genetic causes and were compared with a literature review of 298 cases published before 1982. The mean gestational age at diagnosis varied from 24-29 weeks in the recent series, compared with 31-33 weeks in the earlier series. Genetically transmitted conditions accounted for more than 35% of the fetal and maternal disorders associated with nonimmune hydrops fetalis in the recent series, compared with 21% before 1982. The most frequently identified genetic abnormalities in our review were chromosomal disorders (15.7%), alpha-thalassemia (10.3%), skeletal dysplasia (4%), arthrogryposis multiplex syndromes (1.8%), multiple pterygium syndrome (1.5%), and lysosomal storage disorders (1.0%). These results confirm the need for systematic chromosome analysis in fetuses with nonimmune hydrops. From this review, we conclude that prenatal noninvasive and invasive techniques combined with detailed pathologic studies have improved the accuracy of diagnosis of the underlying causes of nonimmune hydrops fetalis and have influenced the management of these pregnancies.