Antenatal sonographic features of 100 alpha-thalassemia hydrops fetalis fetuses.

OBJECTIVE

To characterize the sonographic findings of alpha-thalassemia hydrops fetalis.

METHODS

Descriptive study of the ultrasound findings in 100 women with antenatal diagnosis of hydrops fetalis due to alpha-thalassemia.

RESULTS

Mean (+/- SD) maternal age was 27.5 + 5.7 years (17-41 years). Mean menstrual age was 31.3 +/- 4.7 weeks (22-42 weeks). All fetuses were stillborn or died very shortly after birth. The indications for sonographic examination included early onset of pre-eclampsia, large for date, decreased fetal movement and nonreactive NST, or bradycardia and premature contractions. The sonographic features found in more than 90% of cases included hepatosplenomegaly, cardiac enlargement, edematous placenta, and ascites. Other common findings were oligohydramnios (82%), subcutaneous edema (75%), decreased fetal movement (74%), cord edema (63%), and enlarged umbilical vessel (62%). Pericardial or pleural effusion was seen in only 15% of cases. None of the fetuses showed any morphological abnormality. Early findings (22-28 weeks) included evidence of a thickened placenta and/or minimal ascites and/or slight cardiomegaly.

CONCLUSIONS

The sonographic characteristics of alpha-thalassemia hydrops fetalis ranged from no obvious morphological abnormalities to evidence of fluid retention. These typical abnormal findings generally did not appear until the late second trimester or early third trimester.