P-772 Assisted reproductive technology and the risk of minor congenital heart defects in the newborn
Authors: Kyhl F , Jensen J  S , Vassard D , Vøgg R  O B , Bundgaard H , Madsen P  L , Pinborg A 
Published: July 2024

Abstract

Study question
Are children conceived through assisted reproductive technology (ART) at higher risk of minor congenital heart defects (CHD) compared with naturally conceived (NC) children?

Summary answer
Contrary to previous studies children conceived through ART had similar risk of minor CHDs compared with children conceived naturally.

What is known already
Congenital heart defects (CHD) may precipitate cardiac arrhythmias, lead to thromboembolic events, culminate in heart failure or even sudden cardiac demise. A systematic review and meta-analysis showed an elevated odds ratio (OR) for diagnosis of any CHD among children conceived through in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) compared with NC children. Other studies indicate that ART is associated with an increased arterial blood pressure and vascular dysfunction in the pulmonary and systemic arterial vasculature. This association persists throughout childhood, adolescence, and early adulthood in individuals conceived through ART; this indicates a lasting impact on the cardiovascular circulatory system.

Study design, size, duration
The present study is a sub-study to the Copenhagen Baby Heart Study (CBHS), a prospective population-based cohort study of &gt; 25 000 children born in the three main maternity wards in Copenhagen, Denmark, in 2016–2018. Transthoracic echocardiography (TTE) was performed on all children within 60 days of delivery and diagnosis of CHD was reviewed by a specialist in paediatric cardiology. Information regarding parental health, pregnancy, delivery, and the newborn was collected through Danish patient registries.

Participants/materials, setting, methods
This study includes all children conceived by ART in the CBHS (n = 1 784), and a matched group (1:4 by maternal age at birth) of NC children (n = 7 141). Exclusion criteria were genetic or chromosomal syndromes and heart surgery. Minor CHD was defined as an atrial (ASD) or ventricular septum defects (VSD), bicuspid aortic valve, coarctation of the aorta, pulmonary stenosis, or patent ductus arteriosus. We calculated ORs using logistic regression analyses.

Main results and the role of chance
The mean maternal age at birth was 34.9 (standard deviation [SD] ±4.4) and 35.1 years (SD ± 4.6) and the newborn mean age at TTE was 12.1 (SD ± 9.3) and 12.2 days (SD ± 9.4) in the ART and NC population, respectively. Parental CHD was registered in 40 (2.2 %) children in the ART group and 121 (1.7 %) in the NC group. Overall, 165 (9.2%) children conceived by ART and 611 (8.6%) NC children were diagnosed with a minor CHD. The most prevalent CHDs were VSD and ASD which accounted for 38.8 % and 35.2 % in children with CHD in the ART group, respectively, and 36.8 % and 33.9 % in children with CHD in the NC group. The unadjusted OR for minor CHD was 1.09 (95% CI 0.91–1.30). Adjustments for maternal age and parental CHD did not change the OR. There were no differences in ORs when stratifying by minor CHD type. We stratified by the method of ART: ICSI and IVF and frozen embryo transfer and fresh embryo transfer, and calculated risk of minor CHD comparing the methods and with NC children. We found no difference in any ORs, crude or adjusted.

Limitations, reasons for caution
Children born preterm, and children with severe minor and major CHDs, were underrepresented in the cohort indicating parents of such children chose not to participate in a research project that would include another hospital visit. Residual confounding is plausible because parental CHD diagnoses were retrieved from patient registries.

Wider implications of the findings
The number of children conceived through ART is increasing each year and previous research have found an increased risk of CHD in children conceived through ART. Our findings indicate no increased risk of minor CHD, providing comforting and significant information for advising individuals considering or undergoing ART treatment.

Trial registration number
NCT02753348