ESHRE 2024: Congenital Heart Defects in Children Born After Assisted Reproductive Technologies: A Large Cohort Study from the Committee of Nordic Assisted Reproductive Technology and Safety (CoNARTaS)
Speaker Nona Sargisian
Congenital heart defects (CHDs) are the most common congenital disabilities, affecting 1-2% of children and accounting for over 50% of major congenital disabilities. They are a significant pediatric health concern and the leading cause of mortality from congenital disabilities, according to the World Health Organization. A study investigated the risk of major CHDs in children born through assisted reproductive technologies (ART) using data from Denmark, Finland, Norway, and Sweden. The ART registries were linked with health and population registries using unique identity numbers, allowing individual-level data linkage between children and their mothers. The study included over 7.7 million live births, with more than 170,000 children born after ART. Stillbirths and terminated pregnancies were excluded due to a lack of data on congenital disabilities. The primary outcome was major CHDs diagnosed prenatally or up to one year of age. Secondary outcomes included severe CHDs, classifications according to the British Pediatric Cardiology Association (BPCA), and ten selected major CHDs. Risks were examined for singletons and multiples, comparing intracytoplasmic sperm injection (ICSI) with in vitro fertilization (IVF) and fresh versus frozen embryo transfers in singletons. The study highlights the importance of monitoring CHD risks in children conceived through ART.
The study found that ART is associated with an increased risk of major and severe CHDs in live-born children, with follow-up to one year of age. Children born after multifetal pregnancies exhibited the highest risk of CHDs, regardless of the mode of conception. ART was also associated with an increased risk of major and severe CHDs in singletons. There were no significant differences in risk between ICSI and IVF or between fresh and frozen embryo transfers in singletons. An analysis of six lesion groups according to the hierarchical classification of the BPCA revealed an increased risk of major CHDs in five groups. Additionally, an increased risk was identified for selected CHDs. These findings indicate that children born through ART exhibit a higher prevalence of major and severe CHDs. The absolute risk remains modest and is primarily linked to multiple pregnancies, which are more prevalent with ART. The importance of single embryo transfer is emphasized to mitigate the increased risk of CHDs associated with multifetal pregnancies.
The study also identified an increased prevalence of CHDs in children conceived through ART, affecting both singletons and multiples. Environmental and genetic factors contribute to CHDs, with parental subfertility being a potential cause. A one-year follow-up period was adequate, as most CHDs are diagnosed within this timeframe. Consistent results across Nordic countries were found despite varying registration practices. Specific groups, such as those with maternal pre-gestational diabetes or congenital heart defects, require closer monitoring. Recent guidelines recommend extra screening for cardiac risk factors, including obesity and IVF treatments. Advancements in prenatal diagnostics have improved CHD detection, impacting reported incidence rates. Multiple pregnancies, especially monochorionic twins, present higher CHD risks. Adjustments for maternal age and other confounders ensured accurate risk assessments linked to ART.
European Society of Human Reproduction and Embryology, July 7-10, Amsterdam, The Netherland
