Assisted reproductive technology poses no excess risk of multiple sclerosis

Exposure to assisted reproductive technology (ART) does not appear to promote the development of multiple sclerosis, a study has found.

In this register-based nationwide cohort study, researchers looked at 585,716 women to compare the incidence of multiple sclerosis among those who had undergone ART treatment and those who had conceived a child without previous ART treatment. ART included in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and fresh embryo transfer with hormone stimulation.

Of the women in the cohort, 63,791 (11 percent) initiated at least one IVF or ICSI cycle during the study period. None of the women had cycles with oocyte donation. The median follow-up duration for the entire cohort was 12.4 years.

Compared with women conceiving without previous ART, those who received ART treatment tended to be older (31.8 vs 27.5 years), have a university degree (45 percent vs 36 percent), and have received other fertility treatments than IVF or ICSI before cohort entry (26 percent vs 3 percent).

Multivariable Cox proportional hazards regression analysis showed no association between incident multiple sclerosis and exposure to ART (adjusted hazard ratio [aHR], 1.08, 95 percent confidence interval [CI], 0.93–1.25). Results were consistent in an analysis that applied intention-to-treat principle in a propensity-score matched subcohort.

In an analysis that included all ART cycles among the ART-treated women, successful ART cycles (pregnancy) were not associated with an increased risk of multiple sclerosis within 2 years of ART cycle start as compared with failed ART cycles (no pregnancy; aHR, 1.01, 95 percent CI, 0.58–1.76).

Meanwhile, there was a nonsignificant trend toward increased risk of multiple sclerosis with increasing numbers of ART cycles, although this was based on small numbers.