PULMONARY ATRESIA WITH INTACT VENTRICULAR SEPTUM - IMPACT OF FETAL ECHOCARDIOGRAPHY ON INCIDENCE AT BIRTH AND POSTNATAL OUTCOME

Background-Fetal echocardiography is widely established in the United Kingdom for prenatal diagnosis of congenital heart disease. This may r esult in a substantial reduction in incidence at birth because of sele cted termination of pregnancy. The objective of this population-based study was to determine the incidence of pulmonary atresia with intact ventricular septum (PAIVS) at birth, the impact of fetal echocardiogra phy on this incidence, and to compare the outcome of cases with and th ose without prenatal diagnosis. Methods and Results-From 1991 to 1995, all infants born with PAIVS and all fetal diagnoses in the United Kin gdom and fire were studied. There were 183 live births (incidence 4.5/ 100 000 live births). The incidence was 4.1 cases per 100 000 live bir ths in England and Wales, 4.7 in Scotland, 6.8 in Eire, and 9.6 in Nor thern Ireland (P = 0.01). There were 86 fetal diagnoses made at a mean of 22.0 weeks of gestation leading to 53 terminations of pregnancy (6 1%), 4 intrauterine deaths (5%), and 29 live births (34%). The inciden ce at birth would be 5.6 per 100 000 births in England and Wales, 5.3 in Scotland, and unchanged in fire and Northern Ireland, if there were no terminations of pregnancy and assuming no further spontaneous feta l deaths (P = 0.28). An initial diagnosis of critical pulmonary stenos is was made in 6 cases, at a mean of 22.3 weeks of gestation with prog ression to PAIVS by 31.4 weeks. Probability of survival at 1 year was 65% and was the same fur live-born infants whether or not a fetal diag nosis had been made. Conclusions-PAIVS is rare, occurring in 1 in 22 0 00 live births in the United Kingdom and Eire. Termination of pregnanc y has resulted in an important reduction in the live-born incidence in mainland Britain.