Psoriatic arthritis disease activity during pregnancy and the first-year postpartum.

Objectives: To evaluate disease activity in the joints and skin during pregnancy and the first-year postpartum in patients with psoriatic arthritis (PsA).

Methods: Women with PsA who were pregnant between 1990 and 2015 with at least 1 clinic visit during pregnancy were identified from the Toronto PsA database. The course of joint and skin disease activity was defined by the following 5 states: improvement, worsening, stable low, stable high, or a mixed. As controls, 67 nonpregnant PsA women were identified and evaluated over a similar timeframe.

Results: Altogether, 29 PsA women with 42 pregnancies were identified. Of the 42 pregnancies, 40 (95%) resulted in normal live birth. Arthritis improved or was stable low activity in 24 (58.5%) of pregnancies. During the postpartum period, 21 (52.5%) had either improvement or stable low PsA activity, whereas 16 (40%) had either worsening or stable high disease activity. The skin activity during pregnancy either improved or stayed in a stable low state in 30 (88.2%), and in the postpartum period there was worsening in 15 (42.9%). A logistic regression analysis revealed a favourable skin disease course during the pregnancy period in the pregnant group compared to the control group (OR = 6.8, p = 0.004), but not in joint disease.

Conclusions: The outcome of pregnancy among patients with PsA is excellent. Arthritis activity trends toward a favourable course while the skin disease shows a favorable course during pregnancy. When compared to controls, pregnancy period has significant beneficial influence only on the skin but not on the joints in PsA.