Atrioventricular Septal Defect in the Fetus – Associated Conditions and Outcome in 246 Cases

PURPOSE: To evaluate the associated conditions and the outcome of atrioventricular septal defects (AVSD) detected in fetal life. MATERIALS AND METHODS: Retrospective review of all cases of AVSD detected prenatally between 1998 and 2006 in two tertiary referral centers in Germany. RESULTS: 246 cases of AVSD were detected in the study period: 129 (52.4 %) chromosomal anomalies; 72 (29.3 %) heterotaxy syndromes; 17 (6.9 %) non-chromosomal malformation syndromes; 16 (6.5 %) isolated complex cardiac malformations; 5 (2.0 %) singular extracardiac malformations; 7 (2.8 %) isolated AVSD. Chromosomal anomalies were detected significantly earlier in pregnancy (p < 0.01). Associated intracardiac malformations were present in 109 / 246 (44.3 %) cases. Fetuses with trisomy 21 were significantly associated with balanced ventricular morphology and isolated AVSD (p < 0.01). Among the 246 cases, 144 (58.5 %) underwent termination of pregnancy, 18 (7.3 %) died in utero, 17 (6.9 %) in the neonatal period and 19 (7.7 %) in infancy. Forty-eight children (19.5 %) survived with a mean follow-up of 34.94 ± 18.6 months. After exclusion of lethal malformations, the survival rate among live births was 64.9 % (48 / 74). Fetuses with trisomy 21 had significantly better survival rates among continued pregnancies (p < 0.01) and significantly higher rates of successful biventricular repair among survivors who received their final corrective procedure (p < 0.01) than fetuses with normal karyotypes. CONCLUSION: Among fetuses with AVSD, those with trisomy 21 are detected earlier in pregnancy, have less distorted cardiac anatomy, higher rates of biventricular repair and better survival rates. Due to the limited sample size in euploid fetuses, it remains unclear whether this apparent protection afforded to Down syndrome accounts also for cohorts with isolated and balanced AVSD.