The number of babies born with a congenital heart abnormality increased by 16% during the first year of the pandemic, according to new analysis by researchers at the University of London.
Congenital heart defects affect about 1 in 110 births globally, and include defects with the heart’s valves, the major blood vessels of the heart and the presence of holes in the heart.
The researchers behind the new study used data for 18 million births in the US between December 2016 and November 2022 in order to investigate the effects of the pandemic on babies born with congenital heart defects.
The data were compared to the number of babies born with Down Syndrome, a genetic condition that is not affected by the COVID-19 virus, in order to ascertain whether the COVID-19 virus is likely to have been responsible, or whether other factors, such as limited access to antenatal services during the pandemic, were at work.
A total of 11,010,764 births before and 7,060,626 births during the pandemic were analyzed. Data were adjusted to account for various confounding factors, including the mother’s BMI, diabetes and blood pressure before pregnancy, age, number of times the mother had given birth and the season in which prenatal care started.
The number of births with a congenital heart condition increased by 16% after the first year of the pandemic, from 56.5 per 100,000 births in the period studied before the pandemic to 65.4 cases per 100,000 live births during the pandemic.
By contrast, the number of babies born with Down Syndrome did not change, which suggests the change in the rate of heart defects was not due to the disruption of health services.
“Studying this large U.S. dataset has revealed an unexpected picture for how the pandemic has affected the hearts of unborn babies, but we need to untangle the reasons for this link,” said lead author Professor Asma Khalil.
“We need to determine if the SARS-CoV-2 virus directly causes the development of fetal heart problems during pregnancy, and if so, how the virus makes these changes in the heart.”
The study did not take into account vaccination status of the mothers (i.e. for COVID-19), or compare the relative rates of heart defects between vaccinated and unvaccinated mothers.