Incidence and outcome of prenatally diagnosed, chromosomally normal congenital heart defects in Singapore

ABSTRACT

<p><b>INTRODUCTION</b>Congenital heart defect (CHD) is a significant cause of neonatal and infant mortality. We aimed to evaluate the incidence and pregnancy outcome of foetuses diagnosed with chromosomally normal CHD in KK Women's and Children's Hospital (KKH), Singapore, in 2008-2009.</p><p><b>METHODS</b>We reviewed the medical records of pregnant women who underwent first trimester screening and were diagnosed with foetal CHD at KKH. Additional information was obtained from the Birth Defect Registry for the period 2008-2009. Foetuses with abnormal karyotype or minor lesions not expected to be detected by ultrasonography were excluded.</p><p><b>RESULTS</b>38 out of 9,834 euploid foetuses were diagnosed with CHD. Major defects were found in 26 (68%) foetuses, while 12 (32%) had minor CHDs. Tetralogy of Fallot, atrioventricular septal defect, hypoplastic left heart syndrome, transposition of the great arteries and ventricular septal defect constituted the five most common major CHDs observed. In 14 (54%) foetuses with prenatally diagnosed major CHD, the outcome was termination of pregnancy, while 12 (46%) pregnancies continued to birth. Among the live-born babies with major CHD, eight (67%) underwent surgery.</p><p><b>CONCLUSION</b>The incidence of non-chromosomal major CHD in Singapore was about 2.6 per 1,000 foetuses. A detection rate of 88.5% was achieved for major CHD during the study period. Advances in CHD management have thrown up new challenges for clinicians in the area of diagnosis, treatment and ethics. Therefore, it may be beneficial to constitute a regulatory entity as a fundamental guide to improve the future management of foetuses diagnosed with CHD.</p>