Background: Ventricular septal defect (VSD) is one of the most common congenital heart disease and has previously been estimated to affect approximately 0.5% of all newborns. The Copenhagen Baby Heart (CBH) study is an ongoing (2016-2018) multi-center, prospective, population survey, offering inclusion of all newborns in the greater Copenhagen area. The CBH study combines echocardiography, ECG and blood sampling with information on pregnancy, delivery, and the parents' lifestyle, socio-economic status and health.
Purpose: To determine the prevalence of VSD by echocardiography and the rate of spontaneous closure during follow-up.
Method: We perform echocardiography within 14 days of birth. Infants identified with a VSD are offered serial follow-up, with echocardiography the first year of life or until VSD closes. As of May 30, 2017, 10.000 newborns had undergone cardiac examinations.
Preliminary results: VSDs were found in 310 newborns (50.6% female), corresponding to a prevalence of 3.1%. A total of 285 (91.9%) were classified as muscular VSDs, of which 41 (14.3%) had multiple VSDs. The remaining 25 (8.1%) were classified as perimembranous VSDs. Echocardiographic follow-up showed spontaneous closure in: 80(78.2%) out of 102 children, 115(76.2%) of 151 children and 129 (76.3%) of 169 children after 3 months ±30 days, 6 months ±30 days and 9 months ±30 days. Thus the prevalence of persistent VSD after 9 months of age was approximately 0.75%. Cox regression analysis showed no statistically significant difference in spontaneous closure in males compared with females (hazard ratio 0.83, 95% CI 0.60-1.15).
Conclusion: Systematic neonatal screening by echocardiography revealed a prevalence of VSDs of 3.1% in newborns and thus higher than previous estimations. Follow-up showed that approximately 75% closed spontaneously and that the vast majority of spontaneous closure happened within the first 3 months of life.