To evaluate pregnancy outcomes in relation to antirheumatic treatment before and during pregnancy as a proxy of disease severity in PsA-pregnancies as compared to non-PsA-pregnancies.
Swedish nationwide register-based cohort study of 921 PsA- pregnancies and 9210 non-PSA-pregnancies (matched 1:10 on maternal age, year, and parity) 2007-2017. We estimated adjusted odds ratios (aOR) overall and stratified by presence, timing, and type of antirheumatic treatment. Adjustments were made for BMI, smoking, educational level and country of birth. The outcome preterm birth was also stratified by parity.
Women with PsA vs. non-PsA-pregnancies were more obese, more often smokers and had a diagnosis of pre-gestational hypertension and diabetes more often. Increased risks in PsA vs. non-PsA-pregnancies were foremost preterm birth (aOR 1.69, 95% CI 1.27-2.24) and cesarean delivery, (aOR 1.77, 95% CI 1.43-2.20 for elective and aOR 1.42, 95% CI 1.10-1.84 for emergency cesarean delivery). The risks differed with presence, timing, and type of antirheumatic treatment with the most increased risks in PsA-pregnancies (vs. non-PsA) with antirheumatic treatment during pregnancy, aOR preterm birth; 2.30, 95% CI 1.49-3.56. Corresponding aOR for biologics exposed PsA-pregnancies was 4.49, 95% CI 2.60-7.79. Risk of preterm birth was primarily increased in first pregnancies.
In comparison with non-PsA-pregnancies risks of preterm birth and cesarean delivery were mostly increased in those exposed to antirheumatic treatment during pregnancy, especially biologics. As parity influences the risk of preterm birth in PsA pregnancies special attention to first pregnancies is warranted. Women with PsA, should receive individualized monitoring during pregnancy.