Prenatal detection of structural cardiac defects and presence of associated anomalies in addition to obstetric outcome: a prospective study of 1244 fetal echocardiograms

Results During the five year period 1244 echocardiographs were recorded, 242 (19. 5%) of which had a structural cardiac defect. The most common defects were AVSD (n=36), VSD (n=26), transpositions (n=15), Hypoplastic Left Heart (n=27)and valvular defects (n=30). Abnormal anatomy scan was the best indicator for detecting the presence of cardiac defects, compared to all other indications (p<0. 0001). Invasive testing was performed for 44% of those identified with a cardiac anomaly, of which 54 (51%) were abnormal karyotypes. Thirty-seven percent (n=89) of those with a cardiac anomaly also had an extra-cardiac defect. In addition these fetuses were significantly more likely to have a karyotypic abnormality when compared with those with an isolated cardiac anomaly (p<0. 0001). In terms of obstetric outcomes pregnancies affected by a major cardiac anomaly had an incidence of 3. 1 per 1000, had a significantly increased risk of pre-term delivery before 34 weeks (OR 3. 2 p=0. 003) and intrapartum emergency caesarean section for a non-reassuring fetal heart rate (OR 2. 2 p=0. 02). The live birth rate in these affected pregnancies was 98% with a 1% neonatal mortality rate. Apgar scores at one and five minutes were significantly better in those babies delivered vaginally compared to those delivered by caesarean section.