Rate of prenatal diagnosis of critical congenital heart disease continued to improve despite COVID‐19 pandemic: multicenter Canadian study

Travel restrictions, reallocation of health resources and physical distancing during the coronavirus disease 2019 (COVID-19) pandemic caused extraordinary strain on healthcare systems. The overall impact of public health measures during COVID-19 on the prenatal diagnosis of congenital heart disease (CHD) has received limited attention. We sought to determine the rate of prenatal diagnosis and the pregnancy and postnatal outcomes of critical CHD prior to and during the COVID-19 pandemic. Cases of critical CHD with estimated due date between 1 January 2016 and 31 March 2022 that required or were expected to require neonatal intervention were identified from all tertiary fetal cardiac centers in Ontario and Alberta, Canada. Pregnancies were stratified based on reaching 18 weeks' gestation before (pre-COVID-19) or after 1 March 2020 (during COVID-19), as the latter group would require ultrasound scanning under COVID-19 pandemic restrictions. Outcomes included timing of critical CHD diagnosis (prenatal or postnatal), gestational age at prenatal diagnosis, pregnancy outcome and infant mortality at 30 days and 1 year after birth. The rate of prenatal diagnosis was assessed using Cox proportional hazard modeling with time-varying and time-invariant cofactors. Prenatal diagnosis occurred in 1238/1774 (69.8%) cases of critical CHD overall, of which 858/1257 (68.3%) cases were in the pre-COVID-19 group and 380/517 (73.5%) cases were in the COVID-19 exposure group (P = 0.03). There was no difference between the pre-COVID-19 group and the COVID-19 exposure group in median gestational age at obstetric ultrasound (20.1 (interquartile range (IQR), 19.0-22.0) weeks vs 19.8 (IQR, 19.1-21.3) weeks; P = 0.07), median time from obstetric ultrasound to diagnosis of critical CHD (1.2 (IQR, 0.6-2.2) weeks vs 1.2 (IQR, 0.6-2.2) weeks; P = 0.59) and prenatal diagnosis < 22 weeks' gestation (454/848 (53.5%) vs 221/378 (58.5%); P = 0.11). Termination of pregnancy was more common in the COVID-19 exposure group (pre-COVID-19, 20.9% vs during COVID-19, 27.5%; P = 0.01). Infant mortality at 30 days (pre-COVID-19, 2.5% vs COVID-19, 1.8%; P = 0.44) and at 1 year after birth (pre-COVID-19, 8.9% vs COVID-19, 8.6%; P = 0.86) did not differ between eras. Once adjusted for province, trends in calendar time, week of gestation, distance to closest tertiary fetal cardiac service and genetic diagnosis, the rate of prenatal diagnosis of critical CHD continued to increase, with a trend towards an increased rate during the COVID-19 pandemic compared with the pre-COVID-19 era. Despite the reduction in clinical services during the COVID-19 pandemic, the rate of prenatal diagnosis of critical CHD continued to increase during the pandemic in two of Canada's largest provinces. These findings provide reassurance regarding the impact of refined fetal cardiology referral indications for resource-limited scenarios. © 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.