A population-based study of caesarean section in women with juvenile idiopathic arthritis.

Objectives: The literature on delivery methods in women with JIA is limited. Active inflammation is a risk factor for caesarean section (CS) in other arthritic diseases. A CS entails a higher risk for complications than vaginal delivery and restricted physical activity in the first weeks after birth. Our objective was to explore a possible association of inflammatory active disease and the proportion of CS in women with JIA.

Methods: Data from the Norwegian nationwide observational register RevNatus were linked with data from the Medical Birth Registry of Norway (MBRN). Cases comprised singleton births in women with JIA ( = 196) included in RevNatus from 2010 to 2019. Singleton births registered in the MBRN during the same period of time, excluding births in mothers with rheumatic inflammatory diseases, served as population controls ( = 575 798).

Results: CS was more frequent in women with JIA (20.4%) and in the subgroup of women with inflammatory active JIA (30.0%) than in population controls (15.6%). Women with active JIA had a risk for elective CS similar to population controls [risk difference 2.3% (95% CI -2.5, 12.9)] and a higher risk for emergency CS [risk difference 14.0% (95% CI 4.3, 27.4)] compared with population controls.

Conclusion: Women with active JIA had a higher risk for emergency CS, but not elective CS, compared with population controls.