Prenatal detection and outcome of major heart defects in a country with universal screening

OBJECTIVE: To evaluate the Danish prenatal screening program for major fetal congenital heart defects (mCHD), focusing on incidence, detection rates (DRs), pregnancy outcomes and postnatal mortality.

METHODS: This was a 5-year nationwide cohort study conducted from January 2018 to December 2022 in Denmark. We included pregnancies suspected of and/or with a confirmed mCHD and children with a confirmed mCHD, and excluded those who were not screened, false-positive cases and those who emigrated before delivery. The main outcome was the prenatal DR of mCHD. Secondary outcomes were rate of termination of pregnancy, liveborn incidence of mCHD, gestational age at delivery, neonatal surgery rate and postnatal mortality.

RESULTS: Data from a total of 645 pregnancies and children with mCHD were retrieved from local databases and 602 were included in the final analysis. The prenatal DR of mCHD was 82.6% (497/602), with one of the highest DRs observed for univentricular heart (99.4% (159/160)) and the lowest DR for total anomalous pulmonary venous return (7.7% (1/13)). Termination of pregnancy occurred in 43.4% (261/602) of cases, with 52.5% (261/497) of prenatally detected cases opting for termination. The liveborn incidence of mCHD was 0.11% (1.1 per 1000 births), and the median gestational age at delivery was 39 + 2 weeks. Surgery was performed in 92.0% (300/326) of liveborn children, primarily within the first month after birth. The postnatal follow-up time was between 8 months and 5 years, with a mortality rate of 9.8% (32/326), of which 50.0% occurred neonatally without surgery.

CONCLUSIONS: This study highlights increased prenatal DRs and a declining liveborn incidence of mCHD in Denmark, underscoring the efficacy of the national screening program and centralized care. Furthermore, the vast majority of patients were treated surgically, and the mortality rate was low. The declining liveborn incidence of mCHD should be monitored and potential causes explored further. © 2025 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.