The ultrasonographic features of nonimmune hydrops fetalis: a study of 30 successive patients.

Nonimmune hydrops fetalis (NHF) is four times as common as the immune form due to the efficacy of anti-D gamma globulin therapy and the lower incidence of Rh incompatibility. Forty successive patients were studied over a 10-year period. The diagnosis of NHF was made prenatally by ultrasonography in all 30 patients who had this examination. Ten patients did not have ultrasonography. NHF usually has a recognizable cause. Of those occurrences diagnosed at less than 21 weeks' gestation, the ultrasonographic features of fetal Turner syndrome--which include NHF--were present in 88.9%. All were fatal. In those diagnosed at over 21 weeks' gestation, the commonest associated disorder was fetal cardiac decompensation (48.3%). Fetal cardiac dysrhythmia was readily identified by real-time ultrasonography. In two patients with fetal supraventricular tachycardia and NHF at 32 weeks' gestation, cardioversion with prenatal digoxin therapy was attempted but was unsuccessful. Fetus-to-fetus transfusion resulted in NHF in only one fetus in each of five multiple pregnancies. NHF was fatal in 80% of newborns. Airway problems and pulmonary hypoplasia were the main causes of death in the neonate. Survivors came from those with tachydysrhythmia, congenital infection, Noonan syndrome, and the idiopathic form of NHF. When NHF is detected ultrasonographically, I recommend fetal cardiac ultrasonography; 2-D, M-mode, and Doppler imaging may also be needed. Fetal supraventricular tachycardia is a remediable condition and treatment in utero should be considered.