Maternal Autoimmune Disease in Pregnancy Tied to Higher Offspring Type 1 Diabetes

Children born to mothers with an autoimmune disease during pregnancy had a higher risk of developing type 1 diabetes (T1D), although similar associations with paternal autoimmune disease suggest a role for shared familial susceptibility, according to a nationwide Swedish cohort study published in JAMA Pediatrics.

The investigators noted that maternal autoimmune diseases during pregnancy may affect offspring risk of immune-mediated disease over the long term, but that it is unclear how much prenatal and familial factors each contribute to offspring T1D. The study examined a broad spectrum of maternal autoimmune diseases and compared maternal and paternal associations.

The population-based cohort study used national health registers to identify 1,455,645 children born in Sweden between 2001 and 2014, who were followed up from birth until T1D diagnosis, death, emigration, or December 31, 2023. During a median follow-up of 15.3 years, 10,273 (0.71%) developed T1D. Maternal autoimmune disease during pregnancy was associated with an increased risk of offspring T1D (adjusted hazard ratio, 1.57; 95% CI, 1.46-1.68).

Paternal autoimmune disease before childbirth showed a similar association, and a direct comparison found no overall difference between maternal and paternal associations, although results varied across specific disease categories. Risk also followed a gradient according to parental T1D status, with the highest risk when both parents had T1D, followed by paternal T1D only and then maternal T1D only. In cousin analyses, which were used to assess the role of shared familial factors, the association with maternal autoimmune disease was attenuated but persisted (hazard ratio, 1.27; 95% CI, 1.08-1.50).

The authors concluded that the similar maternal and paternal associations point to shared familial susceptibility, whereas differences by disease suggest that some conditions may involve parent-specific effects. Overall, they said the findings suggest that both shared familial susceptibility and possible intrauterine mechanisms contribute. 

Source: Zhang H, Janszky I, Arkema EV, et al. Maternal autoimmune diseases during pregnancy and offspring type 1 diabetes. JAMA Pediatr. Published online October 26, 2026. doi:10.1001/jamapediatrics.2026.4894