Mode of Conception and Long‐Term Infectious Morbidity of the Offspring; a Sibling Analysis

Aim To investigate the association between mode of conception, that is, using fertility treatments versus spontaneously conception, and long‐term infectious morbidity of the offspring while employing sibling matched analysis. Methods A retrospective population‐based cohort study was performed, including all sibling deliveries between 1991 and 2021 at a tertiary medical center. Offspring were followed until the age of 18. A Kaplan–Meier survival curve was used to compare the cumulative incidence of infectious morbidity, and a multivariable Cox survival hazards regression model was used to control for confounders. Results During the study period, 14 336 siblings met the inclusion criteria, of which 7711 (53.8%) were conceived through fertility treatments and 6625 (46.2%) were conceived spontaneously. No differences in long term infectious morbidity were demonstrated between siblings conceived following fertility treatments and spontaneously conceived siblings using Kaplan Meier survival curve (Log‐Rank p = 0.614). Likewise, the Cox proportional hazard model did not demonstrate an independent association between mode of conception and long‐term infectious morbidity in the offspring (adjusted HR 0.92, 95% CI 0.85–1.00, p = 0.063) controlling for maternal age, gestational age and follow up time. Conclusion Using a sibling analysis, fertility treatment does not appear to be an independent risk factor for long‐term infectious morbidity of the offspring up to 18 years of age.