Hydrops fetalis in the stillborn: a series from the central region of Thailand.

The purpose of this study was to analyze the cause of hydrops fetalis (HF) among fetal deaths in the central region of Thailand. Autopsy reports diagnosed as HF from 1999 to 2008 at King Chulalongkorn Memorial Hospital were retrieved, and the pathologic findings, clinical information, fetal ultrasonographic studies, and laboratory investigations were reviewed. There were 78 stillborn autopsies during this 10-year period; the mean gestational age was 28 weeks. The causes of fetal hydrops were identified in 88.5%; no cases of immune hydrops were detected. Anemia was the predominant cause of HF (n  =  33; 42.2%): related to homozygous α-thalassemia (n  =  17; 21.8%), twin-twin transfusion syndrome (n  =  8; 10.2%), hemoglobin H (n  =  3; 3.8%), lung hemorrhage (n  =  1; 1.3%), adrenal hemorrhage (n  =  1; 1.3%), and 3 cases of unspecified etiology (3.8%). Other causes of high-output failure included mass lesions resulting in vascular shunting (n  =  2; 2.6%) and 1 case each (1.3% each) of maternal diabetes mellitus, intestinal lymphangiectasia, and Beckwith-Wiedemann syndrome. Causes resulting in low-output cardiac failure were congenital heart disease (n  =  16; 20.5%) and thoracic space-occupying lesions (n  =  7; 9%). The remaining causes included fetal infection (n  =  5; 6.4%), congenital abnormalities suggestive of a chromosomal or genetic basis (n  =  2; 2.6%), and 1 case (1.3%) of placental vascular thrombosis. Nine cases (11.5%) had no identifiable cause. Thus, the most common cause of HF in this series was homozygous α-thalassemia, reflecting the geographic location of this series.