P06.11: The association of congenital cardiac defects with aneuploidy, extra‐cardiac defects and obstetric outcomes: a prospective study

Abstract

To document detection of congenital heart defects (CHDs) in relation to (i) the indication for referral for fetal echocardiography, (ii) associated extra-cardiac anomalies, (iii) karyotypic abnormalities and (iv) obstetric and neonatal outcomes. This was a prospective study from 2007-2011 inclusive. Data were recorded for fetal echocardiography and analyzed for referral indication, presence of extra-cardiac anomalies and invasive testing. For analysis of obstetric and neonatal outcomes the fetal echocardiography group were compared to a control group of 45,069 non-anomalous singleton pregnancies. Overall 1244 echocardiographs were recorded, 242 (19.5%) of which had a CHD. The commonest defects were AVSD (n = 36) and VSD (n = 26). Abnormal anatomy scan was the best indicator for detecting the presence of CHDs, compared to all other indications (p < 0.0001). Invasive testing was performed for 44% of those identified with a CHD, of which 54 (51%) were abnormal karyotypes. Thirty-seven percent (n = 89) of those with a CHD 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 CHD (p < 0.0001). In terms of obstetric intervention, pregnancies affected by a major CHD were significantly more likely to require an emergency caesarean section (CS) for a non-reassuring fetal heart rate (NRFHR) (p = 0.022) and were more likely to go into preterm labour prior to 34 weeks (p = 0.003). Despite this, fetuses affected by CHD delivered vaginally had higher APGAR scores than those delivered by CS at one (p = 0.01) and five (p = 0.04) minutes. This study suggests most CHDs occur in a low risk population. Significant numbers of chromosomal and extra-cardiac defects in this study emphasize the importance of thorough evaluation of any fetus identified with a cardiac defect. Pregnancies with CHD are more at risk of requiring an emergency CS in labour although vaginal delivery is otherwise a safe option.