POS1000 MORE THAN 30 % OF WOMEN WITH SPONDYLOARTHRITIS HAVE AN UNFAVORABLE PREGNANCY OUTCOME MOST FREQUENTLY DUE TO SMALL FOR GESTATIONAL AGE: ANALYSIS OF THE PROSPECTIVE GR2 COHORT

Abstract

BackgroundSpondyloarthritis (SpA) 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.ObjectivesThe aim of the study was to determine the factors associated with adverse pregnancy outcome in women with SpA.MethodsAll SpA 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. 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). Disease activity was defined by a BASDAI score ≥ 4 at least once during pregnancy. We used a multiple imputation to address missing data among the explanatory variables. Results are presented as an odds ratio (OR) with confidence interval (CI).ResultsAmong the 207 pregnancies in women with SpA included in the GR2 cohort, 126 were retained for analysis of obstetrical outcome. Of these, 29 (23.0%), 14 (11.1%), 69 (54.8%) were exposed to corticosteroid, NSAID and biologics at least once during pregnancy, respectively. An active disease at least once during pregnancy was found in 47 (37.3%) pregnancies. A live birth was found in 116 (92.1%) women, including 110 (87.3%) full-term births. Early miscarriages and stillbirths were observed in 7 (0.06%) and 3 (0.02%) women, respectively. A caesarean section was performed in 20 (17.2%) cases.A favorable pregnancy outcome was found in 80 (63.5%) of the women. Unfavorable pregnancy outcome was most frequently due to small for gestational age, observed in 22 (19%) pregnancies. The multivariate model adjusted for age, BMI, nulliparity, active disease during pregnancy, smoking, and exposure to NSAIDs and corticosteroids during pregnancy found an association between unfavorable pregnancy outcome with nulliparity (OR 2.63 95% CI [1.01-6.81] p = 0.05).ConclusionThis study provides original results on pregnancy in women with SpA. It found a favorable pregnancy outcome in 63.5% of women. Unfavorable pregnancy outcome was most frequently due to small for gestational age, which should lead to a coordinated management with obstetricians for the follow-up of pregnancy in women with SpA.