Assisted Reproductive Technology Linked to Modestly Higher Childhood Cancer Risk

Children conceived using assisted reproductive technology (ART) had a modestly higher incidence of childhood cancer than children conceived without ART in a nationwide Danish cohort study published as a brief report in JAMA. Higher incidence was seen mainly after frozen embryo transfer and intracytoplasmic sperm injection, and the investigators reported that absolute risks were low.

The investigators noted that uncertainty remains about childhood cancer risk after ART, especially by procedure and cancer type, and they analyzed associations overall as well as by modality and cancer type.

The cohort comprised 1,086,136 live-born children from 1996 to 2012, followed through 2023; 37,228 (3.4%) were conceived using ART. Maternal ART was categorized as in vitro fertilization (IVF), intracytoplasmic sperm injection, or frozen embryo transfer, and non-ART births served as the primary reference group. Over a median follow-up of 20 years, 3,736 cancers occurred. Incidence was 23.6 per 100,000 person-years among children conceived using ART vs 18.3 per 100,000 among non-ART births (hazard ratio, 1.26; 95% CI, 1.07-1.48).

Incidence was 41.1 per 100,000 person-years after frozen embryo transfer and 27.9 per 100,000 after intracytoplasmic sperm injection. The analysis did not show a higher rate after IVF (18.5 per 100,000; hazard ratio, 1.01; 95% CI, 0.79-1.28). By cancer type, frozen embryo transfer was associated with leukemia, lymphomas, and soft tissue sarcomas, and intracytoplasmic sperm injection with lymphomas, soft tissue sarcomas, and central nervous system neoplasms; confidence intervals around these estimates were wide. No cancer type–specific associations were observed for IVF.

Findings were similar when the reference group was instead children of women with a history of infertility or children conceived using IVF. The investigators said this consistency suggests that factors related to the procedures themselves, rather than to infertility, merit further investigation.

Source: Mose K, Kjaer SK, Jensen A, Grell K, Pottegård A, Hargreave M. Childhood cancer risk after assisted reproductive technology. JAMA. Published online October 21, 2026. doi:10.1001/jama.2026.18862