A retrospective review of fetuses diagnosed with AVSD was conducted.
Of 106 fetuses with AVSDs, outcome data were available in 88, 66 with situs solitus and 22 with heterotaxy. Overall mortality was 52 % , with 66 % surviving to birth, 58 % to 1 month, and 47 % to 1 year. There was increased mortality in patients with heterotaxy (P?= .02). In patients with situs solitus, there was increased mortality in those with unbalanced AVSDs (P < .01). The presence of a chromosomal abnormality did not affect mortality (P?= .34). In pregnancies with intent to continue (n?= 60), 97 % of patients survived to birth, 86 % to 1 month, and 69 % to 1 year. The presence of heterotaxy (P < .01) or other complex intracardiac disease (P?< .01) was associated with single-ventricle repair. In patients with unbalanced AVSDs who underwent surgery, two-ventricle repair was uncommon (29 % ), but it was performed more often in those with restrictive ventricular septal defects (71 % ). In the 16 patients with unbalanced AVSDs who underwent multiple studies, 12 showed no change in left atrioventricular valve/right atrioventricular valve ratio from first to the final fetal echocardiographic study; in three patients, this ratio worsened, and in one patient, it improved.
Prenatal diagnosis of AVSD should prompt assessment for chromosomal abnormalities, additional cardiac anomalies, and heterotaxy syndrome. Heterotaxy, unbalanced AVSD, and the need for single-ventricle repair are associated with a poor prognosis. Left atrioventricular valve/right atrioventricular valve ratio early in gestation does not always predict this ratio at delivery.