Differences in growth, weight and body fat levels of children conceived through fertility treatment are small and no longer apparent in late adolescence, a new study finds. The study, led by the University of Bristol, published in JAMA Network Open today [July 26], sought to address concerns about whether fertility treatment is associated with growth, weight, and body fat from infancy to early adulthood.
Since the first birth of a child through in vitro fertilization (IVF), questions have been raised about the risks to children conceived in this way. While previous studies have shown an increased risk of low birth weight and preterm birth in offspring conceived by assisted reproductive technology (ART), relatively little is known about long-term growth and weight gain.
The study, led by an international research group from the Assisted Reproductive Technology and Future Health (ART-Health) Cohort Collaboration, assessed whether conception by ART, which mostly involves IVF, was associated with height, weight and body fat from infancy to infancy. adulthood.
Using data on 158,000 European, Asian-Pacific and Canadian children conceived by ART, the data sample included 8,600 children from Bristol’s Children of the 90s study, a world-leading Bristol-based health study that has followed 14,000 pregnant women and their offspring since then. 1991.
The team’s findings show that those conceived using ART were on average shorter, lighter and thinner from infancy to early adolescence compared to their naturally conceived peers. However, the differences were small at all ages and decreased with older age.
Dr Ahmed Elhakeem, Senior Research Fellow in Epidemiology at Bristol Medical School: Population Health Sciences (PHS) at the University of Bristol, and lead author of the study, said: “This is important work. Over the last three decades the conception by ART has increased. In the UK just over one in 30 children have been conceived by ART, so we would expect on average one child in every primary school class to have been conceived in this way. Since the first birth of a child with IVF, concerns have been raised about the risks to the conceived children.
“Parents and their ART-conceived children may be reassured that this may mean they are slightly smaller and lighter from infancy to adolescence, but these differences are unlikely to have any health implications. We accept that it is important that as more people become ART-conceived adults, we continue to explore any potential health risks in older age.”
This important research is only possible through large-scale international collaboration and longitudinal health studies, where participants contribute health data throughout their lives. We are especially grateful to the European Research Council and Horizon 2020 for making this possible and to all the participants and researchers in the study.”
Deborah Lawlor, professor of epidemiology, MRC investigator and chair of the British Heart Foundation and senior author from Bristol Medical School PHS
Peter Thompson, Chief Executive of the Human Fertilization and Embryology Authority (HFEA), said: “Around 1 in 7 couples have difficulty conceiving in the UK, leading to around 53,000 patients a year undergoing fertility treatment ( (IVF or Donor Insemination).The findings from this study will come as a welcome relief to these patients who begin treatment with the hope of one day having healthy children of their own.
“Health outcomes in children conceived using assisted reproductive technology are a high priority for the HFEA and we monitor the latest research and provide information for patients and professionals. Anyone considering fertility treatment can access this and information other high quality impartial fertility treatments and UK licensed Clinics at www.hfea.gov.uk.”
Studies with larger samples at older ages are now needed. Other outcomes such as cardiometabolic risk factors after ART also require investigation. The collaborative network developed as part of the study will facilitate future research on health outcomes after ART.
The study, funded by the European Research Council under the European Union’s Horizon 2020 research and innovation programme, the Medical Research Council (MRC), the British Heart Foundation (BHF) and the National Institute for Health and Care Research at Bristol Biomedical Research Center (NIHR Bristol BRC), will be presented next month [27-31 August] World Congress DOHAD 2022.
Elhakeem, A., et al. (2022) Association of Assisted Reproductive Technology with Offspring Growth and Adiposity From Infancy to Early Adolescence. Journal of the American Medical Association. doi.org/10.1001/jamanetworkopen.2022.22106.