Pregnancy Outcomes in Patients with Psoriatic Arthritis

Background & Objectives

Studies describing maternal and neonatal pregnancy outcomes in women with psoriatic arthritis (PsA) are few, but some indicate an increased risk of preterm birth and cesarean delivery. In a previous study of 541 pregnant women with PsA, Remaeus et al. concluded that a diagnosis of PsA is associated with preterm birth, cesarean delivery and other adverse pregnancy outcomes, after taking into account comorbidities and confounders (e.g., smoking, body mass index [BMI], and maternal age). Studies on pregnancy outcomes in women with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) indicate that disease activity/severity play a key role in outcomes, underscoring the importance of keeping disease activity low in these women both before and during pregnancy. Corresponding data on disease activity/severity and its impact on maternal and neonatal outcomes in women with PsA are scarce, although increased risk of moderately preterm birth was associated with a high score in the Health Assessment Questionnaire (HAQ) in gestational week 32 in one prospective cohort study.

Because ongoing anti-rheumatic treatment around the time of pregnancy is often required to control PsA disease activity, it can be hypothesized that women treated with anti-rheumatic drugs before and/or during pregnancy have more severe and active disease than untreated women. On the other hand, anti-rheumatic treatment may improve clinical and inflammatory measures. Thus, it’s important to consider the history of anti-rheumatic treatment before pregnancy when evaluating pregnancy outcomes.

Remaeus et al. set out to evaluate pregnancy outcomes in relation to anti-rheumatic treatment, which was used as a proxy for disease severity in pregnancies of women with PsA compared with pregnancies in women without PsA. Specifically, they wanted to assess this in relation to the timing and type of anti-rheumatic treatment.

Methods

This study focused on a Swedish nationwide registry-based cohort study that included 921 pregnant women with PsA and 9,210 pregnant women without PsA between 2007 and 2017 (matched 1:10 based on maternal age, year of birth and parity). The researchers estimated adjusted odds ratios (ORs) overall, with 95% confidence intervals (95% CIs), and stratified by presence, timing and type of anti-rheumatic treatment. Adjustments were made for maternal body mass index, smoking, educational level and country of birth. The outcome of preterm birth was also stratified by parity.

Results

Pregnant women with PsA vs. those without PsA were more obese, more often smokers, and more frequently had a diagnosis of pregestational hypertension and diabetes mellitus. Increased risks in pregnant women with PsA and pregnant women without PsA 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 anti-rheumatic treatment, with the most increased risk in pregnant women with PsA occurring with anti-rheumatic treatment during pregnancy (adjusted OR for preterm birth 2.30 [95% CI 1.49–3.56]). 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.