Peripheral psoriatic arthritis (PsA) disease activity diminished during pregnancy and escalated 6 months after childbirth, according to a study recently published in Arthritis Care & Research. By 1 year postpartum, disease activity tended to stabilize to baseline levels.
This study included a total of 108 pregnancies among 103 women with peripheral PsA, with a mean age of 31 years and a median disease duration of 8 years. Disease activity scores were measured using the 28-joint Disease Activity Score using C-reactive protein (DAS28-CRP-3) and the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).
Low mean disease activity scores were observed across the cohort at baseline, though this varied significantly over time (P =.018). Though disease activity decreased before conception and during pregnancy, it increased and peaked 6 months after childbirth. The 6-month disease activity was greater than it had been at 6 weeks (mean DAS28 score, 2.71 vs 2.45; P =.016), and BASDAI showed similar trends. Full data were available for 53 women, 21% of whom had a postpartum DAS28 increase of at least 1.2, 2% of whom experienced a decrease of 1.2, and the rest of whom had a smaller increase. The use of tumor necrosis factor inhibitors (TNFi) was significantly associated with lower disease activity, with a DAS28 score of 2.22 for users and 2.72 for nonusers at 6 months (P =.043).
A linear mixed model was used to examine DAS28-CRP-3 and BASDAI scores at multiple time points throughout the study period. The Psoriasis Area and Severity Index was used to measure psoriatic activity. Self-reporting using the RAND 36-Item Health Survey and the Modified Stanford Health Assessment Questionnaire was used to gather information on bodily pain, mental health, and physical functioning.
The study researchers concluded that “the majority of women experienced stable, low disease activity. However, disease activity tended to decrease in pregnancy, increased significantly by  months postpartum, before returning to baseline by  year postpartum. Women using TNFi in pregnancy had significantly lower disease activity throughout the study period.”
Ursin K, Lydersen S, Skomsvoll JF, Wallenius M. Disease activity of psoriatic arthritis during and after pregnancy: a prospective multicenter study [published online September 7, 2018]. Arthritis Care Res (Hoboken). doi: 10.1002/acr.23747