Parental Autoimmune Diseases Linked to Increased Type 1 Diabetes Risk in Offspring, Suggests JAMA Study
Sweden: A population-based cohort study found that maternal autoimmune diseases during pregnancy were associated with an increased risk of type 1 diabetes (T1D) in offspring. Similar associations between maternal and paternal autoimmune diseases suggest that shared familial susceptibility plays a key role in the intergenerational transmission of T1D risk. However, disease-specific differences indicate that certain autoimmune conditions may also exert parent-specific effects, potentially involving intrauterine mechanisms.
Published in JAMA Pediatrics, the study was led by Huan Zhang of the Department of Global Public Health, Karolinska Institutet, Stockholm, Sweden, and colleagues. The researchers investigated whether autoimmune conditions in mothers during pregnancy were associated with T1D in children and assessed the extent to which familial factors might explain this relationship.
Autoimmune diseases occur when the immune system mistakenly attacks the body's own tissues. Since type 1 diabetes is also an autoimmune condition, researchers have examined whether parental autoimmune disorders could indicate an increased susceptibility to the disease in children.
For the study, researchers analysed national health register data covering 1,455,645 children born in Sweden between 2001 and 2014. Participants were followed from birth until a T1D diagnosis, death, emigration or December 31, 2023. The median follow-up period was 15.3 years.
The researchers assessed parental autoimmune diagnoses recorded before or during pregnancy and examined their associations with newly diagnosed T1D in offspring. Statistical models accounted for relevant factors, while comparisons between maternal and paternal conditions and additional analyses involving cousins helped explore the potential contribution of shared familial susceptibility.
The key findings were:
- Maternal autoimmune diseases: Children whose mothers had an autoimmune disease during pregnancy had a 57% higher risk of developing T1D than those without the maternal exposure.
- Paternal autoimmune diseases: Autoimmune diseases in fathers before childbirth were associated with a 51% higher risk of T1D in offspring, broadly comparable to the maternal association.
- Parental comparisons: The overall difference between maternal and paternal associations was not statistically significant, although variations emerged across specific autoimmune disease categories.
- Parental diabetes history: T1D risk followed a gradient according to parental T1D status, with the highest risk among children whose both parents had T1D, followed by those with an affected father and those with an affected mother.
- Cousin analysis: The association between maternal autoimmune disease and offspring T1D weakened but remained significant, with a hazard ratio of 1.27, suggesting that shared familial factors explained part, but not all, of the association.
- During follow-up, 10,273 children, representing 0.71% of the cohort, developed T1D.
The authors concluded that familial susceptibility likely contributes substantially to the relationship between parental autoimmune diseases and childhood T1D. However, differences across specific conditions leave open the possibility that pregnancy-related biological mechanisms may also influence disease risk.
The findings do not establish that maternal autoimmune diseases directly cause T1D in children. Further research is needed to clarify the underlying mechanisms and determine whether particular maternal conditions carry distinct risks for offspring.
Reference:
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
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