Risk for adverse pregnancy outcome in axial spondyloarthritis and rheumatoid arthritis: disease activity matters

To analyse pregnancy outcome and delivery mode in patients with RA and axial spondyloarthritis (axSpA) in relation to disease activity and anti-rheumatic drugs.

Patients with RA and axSpA were compared with age-matched healthy controls (HCs) with respect to pregnancy outcome and delivery mode. Disease activity (DAS28, ASDAS, CRP) and medication use of patients was assessed once at each trimester. ORs with 95% CI were calculated with univariate and multivariate regression models.

We analysed 244 pregnancies, of which 96 occurred in patients with RA, 78 in patients with axSpA and 70 in HCs. The adjusted analysis showed that pregnant women with RA and axSpA had a higher risk of pregnancy complications (gestational diabetes, preeclampsia, infection, preterm premature rupture of membranes), small for gestational age infants and preterm deliveries (all P < 0.05). Active disease was a predictor for preterm delivery in both RA [odds ratio (OR) = 3.9, 95% CI: 1.25, 12.15] and axSpA (OR = 13.8, 95% CI: 1.33, 143.94). Regarding delivery mode, most patients had vaginal deliveries. However, women with RA revealed an increased risk of caesarean section compared with HC (P < 0.05), which was not seen in patients with axSpA.

Our findings show that disease activity of RA and axSpA during pregnancy influences pregnancy outcome. To allow for successful pregnancy a treatment strategy that targets inactive disease beyond conception should be followed.