Pregnancy Outcomes in Women With Psoriatic Arthritis In Relation To Presence and Timing of Antirheumatic Treatment

Objective To evaluate pregnancy outcomes in relation to antirheumatic treatment before and during pregnancy, as a proxy of disease severity in pregnant women with psoriatic arthritis (PsA), compared to those without PsA. Methods Our study focused on a Swedish nationwide registry-based cohort study that included 921 PsA pregnancies and 9,210 non-PsA pregnancies occurring between 2007 and 2017 (matched 1:10 based on maternal age, year of delivery, and parity). We estimated adjusted odds ratios (ORs) overall, with 95% confidence intervals (95% CIs), and stratified by presence, timing, and type of antirheumatic treatment. Adjustments were made for maternal body mass index, smoking, education level, and country of birth. The outcome of preterm birth was also stratified by parity. Results Pregnant women with PsA versus those without PsA were more obese, more often smokers, and more frequently had a diagnosis of pregestational hypertension and diabetes mellitus. Increased risks in PsA pregnancies versus non-PsA pregnancies were primarily preterm birth (adjusted OR 1.69 [95% CI 1.27-2.24]) and cesarean delivery (adjusted OR 1.77 [95% CI 1.43-2.20] for elective delivery, and adjusted OR 1.42 [95% CI 1.10-1.84] for emergency delivery). The risks differed according to the presence, timing, and type of antirheumatic treatment, with the most increased risk in PsA pregnancies (versus non-PsA) occurring with antirheumatic treatment during pregnancy (adjusted OR 2.30 [95% CI 1.49-3.56] for preterm birth). The corresponding adjusted OR for preterm birth in women with PsA who were exposed specifically to biologic treatment during pregnancy was 4.49 [95% CI 2.60-7.79]. Risk of preterm birth was primarily increased in first pregnancies. Conclusion Compared to non-PsA pregnancies, risks of preterm birth and cesarean delivery were mostly increased in those exposed to antirheumatic treatment during pregnancy, especially biologic treatments. As parity influences the risk of preterm birth in women with PsA, special attention to first pregnancies is warranted. Women with PsA should receive individualized monitoring during pregnancy.