Caesarean section in women with axial spondyloarthritis and psoriatic arthritis: a population-based study.

Background: There is sparse documentation on pregnancy outcomes in women with axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA). Data on disease activity are often lacking, preventing the direct investigation of the effect of inflammation on pregnancy outcomes. A caesarean section (CS) implies a higher risk for complications than vaginal delivery. It delays mobilisation after birth necessary to counteract inflammatory pain and stiffness.

Objective: To explore a possible association of inflammatory active disease and CS rates in women with axSpA and PsA.

Methods: Data from the Medical Birth Registry of Norway (MBRN) were linked with data from RevNatus, a Norwegian nationwide observational register recruiting women with inflammatory rheumatic diseases. Singleton births in women with axSpA (n=312) and PsA (n=121) included in RevNatus 2010-2019 were cases. Singleton births, excluding mothers with rheumatic inflammatory diseases, registered in MBRN during the same period time (n=575 798) served as population controls.

Results: CS occurred more frequently in both axSpA (22.4%) and PsA (30.6%) groups compared with population controls (15.6%), with even higher frequencies in inflammatory active axSpA (23.7%) and PsA (33.3%) groups. Compared with population controls, women with axSpA had higher risk for elective CS (risk difference 4.4%, 95% CI 1.5% to 8.2%) but not emergency CS. Women with PsA had higher risk for emergency CS (risk difference 10.6%, 95% CI 4.4% to 18.7%) but not elective CS.

Conclusion: Women with axSpA had higher risk for elective and women with PsA for emergency CS. Active disease amplified this risk.