Background Rheumatoid arthritis (RA) is one of the most common chronic inflammatory diseases and regularly affects women of childbearing age¹. However, there is limited knowledge about the impact of the disease and its treatment on pregnancy.

Objectives The aim of the study was to determine the factors associated with adverse pregnancy outcome in women with RA.

Methods All RA patients (diagnosis according to the Rheumatologist) included in the national multicenter GR2 cohort from 2015 to June 2021 were included in the analysis. Patients could be included either with a pregnancy wish (i.e., preconceptional period) or because of a clinical pregnancy (<12 weeks of gestation). The main endpoint was favorable pregnancy outcome, a composite outcome defined as a live birth at term ≥ 37 gestation weeks of a healthy newborn with a weight greater than the 10th percentile. Disease activity was defined by a DAS28-CRP score > 3.2 at least once during pregnancy. We performed a multilevel logistic regression model, in which we considered patient and center random effects (patient random effect for some women included in the cohort two times). We used a multiple imputation procedure to address missing data among the explanatory variables. Results are presented as an odds ratio (OR) with confidence interval (CI).

Results Among the 167 pregnancies in women with RA included in the GR2 cohort, 92 were retained for analysis of obstetrical outcome. Of these, 43 (46.2%), 8 (7.9%), 40 (43.5%) were exposed to corticosteroid, NSAID and biologics at least once during pregnancy, respectively. A moderate or severe disease activity at least once during pregnancy was found in 20 (21.8%) pregnancies. A live birth was found in 83 (90.2%) women, including 69 (83.1%) full-term births. Early miscarriages were observed in 9 (0.1%) women. A caesarean section was performed in 22 (23.9%) cases.

A favorable pregnancy outcome was found in 52 (56.5%) of the women. Unfavorable pregnancy outcome was mainly due to prematurity and small for gestational age, observed in 14 (16.9%) and 17 (20.5%), respectively. The multivariate model adjusted for age, BMI, nulliparity, active disease during pregnancy, smoking, and exposure to biologics and corticosteroids during pregnancy found an association between an unfavorable pregnancy outcome and nulliparity (OR 6.2 95% CI [2.1-17.8] p = 0.002), age (OR (per year) 1.1 95% CI [1.0-1.3] p = 0.02) and exposition to corticosteroids during pregnancy (OR 3.2 95% CI [1.1-9.6] p = 0.04).

Conclusion This study provides original results on pregnancy in women with RA. It found a favorable pregnancy outcome in 56.5% of women. Unfavorable pregnancy outcome was associated with age, nulliparity and corticosteroids use during pregnancy, which argues for their careful use during pregnancy.

References [1]Van den Brandt S. Arthritis Res Ther. 2017;19(1):64.

Acknowledgements The GR2 Cohort is supported by the French Society of Rheumatology, the French Internal Medicine Society, and unrestricted grants from UCB.

Disclosure of Interests SABRINA HAMROUN: None declared, Marion Couderc: None declared, Rene-Marc Flipo: None declared, Laure Gossec: None declared, Christophe Richez Speakers bureau: CR has received consulting/speaker’s fees from Abbvie, Amgen, Astra Zeneca, Biogen, BMS, Celltrion, Eli Lilly, Galapagos, GSK, MSD, Novartis, and Pfizer, all unrelated to this manuscript., Rakiba Belkhir: None declared, Aline Frazier-Mironer: None declared, Valerie Devauchelle-Pensec: None declared, Hubert MAROTTE: None declared, Jérémie SELLAM: None declared, Elisabeth Gervais: None declared, Alban Deroux: None declared, Cédric Lukas: None declared, Emmanuelle Dernis: None declared, Emmanuel Chatelus: None declared, Nathalie Costedoat-Chalumeau: None declared, Anna Moltó: None declared