Higher risk of heart defects in children conceived through assisted reproductive technology in Nordic countries

A recent comprehensive study indicates a higher risk of heart defects in children conceived through assisted reproductive technology (ART). Signe Opdahl, a researcher involved in the study, noted that the investigation, which draws on birth records from across the Nordic countries, analyzed nearly 8 million births in Norway, Sweden, Denmark, and Finland up to 2015. Out of these, approximately 172,000 were born as a result of assisted conception.

The findings revealed that nearly 2% of children conceived via ART were diagnosed with heart defects, compared to just over 1% of those conceived naturally. However, serious heart defects requiring immediate medical intervention were less common, affecting about 600 out of the 172,000 ART-conceived children, which is well below 1%.

Opdahl emphasized that while the absolute risk remains low, it is crucial to monitor these cases, particularly for families affected by heart disease in their children. Liv Bente Romundstad, another researcher, pointed out that advancements in ART techniques since 2015 have significantly contributed to this issue. Historically, multiple embryos were implanted, increasing the likelihood of twins, who have a higher risk of congenital heart defects. Current practices focus on transferring one embryo at a time, thereby reducing not only the risk of heart defects but also premature births and low birth weight.

Despite these advancements, researchers observed an elevated risk of heart defects even in singleton pregnancies conceived through ART, although the reasons remain unclear. Factors related to the underlying infertility of parents may contribute to this increased risk, although the exact causes continue to be investigated. Overall, around 5% of births in Norway today involve ART, a figure expected to rise in the coming years.