The risks for preterm birth and cesarean delivery are increased for pregnancies among women with psoriatic arthritis (PsA), and these risks vary with the presence, timing, and type of antirheumatic treatment, according to a study published online Oct. 20 in Arthritis & Rheumatology.

Katarina Remaeus, Ph.D., from the Karolinska Institutet in Stockholm, and colleagues conducted a nationwide register-based cohort study of 921 PsA pregnancies and 9,210 non-PsA pregnancies between 2007 and 2017.

The researchers found that women with PsA pregnancies were more often obese, more often smokers, and more likely to have a diagnosis of pregestational hypertension and diabetes compared with women with non-PsA pregnancies. Increased risks in PsA pregnancies were most pronounced for preterm birth and both elective and emergency cesarean delivery compared with non-PsA pregnancies (adjusted odds ratios, 1.69, 1.77, and 1.42, respectively). Risks varied with presence, timing, and type of antirheumatic treatment; risks were most increased in PsA versus non-PsA pregnancies with antirheumatic treatment during pregnancy (adjusted odds ratio for preterm birth, 2.30). For biologics-exposed PsA pregnancies, the corresponding adjusted odds ratio was 4.49. Preterm birth risk was mainly increased in first pregnancies.

"From a clinical point of view, all women with PsA, regardless of antirheumatic treatment, should be counselled about pregnancy outcomes and receive individualized monitoring during pregnancy," the authors write.