Evaluation of pregnancy outcomes in patients with spondyloarthritis compared to the general population: results from a French national prospective and matched study.

OBJECTIVES

The aim of the study was to determine the frequency of adverse pregnancy outcomes in women with spondyloarthritis (SpA) in comparison to controls from the French general population, and to identify factors associated with these adverse pregnancy outcomes.

METHODS

This French prospective multicentre cohort study included pregnant women with SpA (both axial and peripheral) according to their treating rheumatologist between December 2015 and June 2021. Maternal characteristics, disease activity, treatments, and pregnancy outcomes were analysed. Outcomes of pregnancies in women with SpA were compared to that of matched (1:4) general population women from the 2016 and 2021 French National Perinatal Surveys, including pregnancy, neonatal, and maternal outcomes. For adverse pregnancy outcomes that are significantly more frequent in patients with SpA, logistic regression analysis was performed to identify potential risk factors.

RESULTS

A total of 135 SpA pregnancies in 124 women were analysed: they have a mean age of 32.1 years, a mean disease duration of 6.3 years, and 50.4% were nulliparous. Small for gestational age (SGA) was the most common adverse pregnancy outcome and occurred more frequently in women with SpA compared to controls (17.4% vs 9.8%, odds ratios = 1.94, 95% CI 1.09-3.39). Other adverse pregnancy outcomes rates, including preterm birth and caesarean delivery, were comparable to the general population. No predictor of SGA was identified in women with SpA.

CONCLUSIONS

In this contemporary cohort, compared to the general population, SpA was associated with a higher risk of SGA, but no other adverse pregnancy outcomes, providing reassurance for most pregnant women with SpA.