Prenatal diagnosis of structural heart disease: does it make a difference to survival?
- Correspondence to:
Dr Ian D Sullivan, Great Ormond Street Hospital for Children, London WC1N 3JH, UK;
sullii{at}gosh.nhs.uk
Is there a survival advantage conferred by the prenatal diagnosis of congenital heart disease?
There are two potential advantages of mid trimester diagnosis of fetal heart disease. Perinatal management in an environment where the appropriate expertise is available and prepared might result in improved outcomes after intervention in the newborn period in situations where this is required. Alternatively, prenatal diagnosis of congenital heart disease allows consideration of termination of pregnancy. Termination of pregnancy for fetal anomaly is an emotive subject and has a wide range of acceptability in different societal contexts. Nearly 20% of all pregnancies in the UK were terminated for social indications in 1994 whereas the proportion in which the indication for termination was detection of fetal cardiac abnormality was about 0.02%.1
SURVIVAL ADVANTAGE?
If there is a survival advantage conferred by the prenatal diagnosis of congenital heart disease, its demonstration has been elusive. The spectrum of heart abnormalities diagnosed prenatally differs from that seen in postnatal practice. Complex cardiac abnormalities, associated extracardiac abnormalities, and chromosome defects are over represented.2 It is not therefore surprising that outcomes for unselected series of structural cardiac abnormalities diagnosed prenatally have been poor, with high rates of spontaneous intrauterine or early neonatal death in continuing pregnancies.
Intuitively, it might be thought that the most likely survival advantage conferred by prenatal diagnosis would occur in isolated cardiac abnormalities in which the natural history would be for early neonatal death to occur because of dependency of either systemic or pulmonary blood flow on continued patency of the arterial duct. Early encouragement for this view was provided by data which indicated that neonates born with hypoplastic left heart …
