OP0126 ARE WOMEN WITH SPONDYLOARTHRITIS AT INCREASED RISK OF ADVERSE MATERNAL AND INFANT OUTCOMES? – A SWEDISH COHORT STUDY

Abstract

BackgroundAn increased risk of adverse pregnancy and neonatal outcomes has been reported for pregnancies in women with several rheumatic diseases including rheumatoid arthritis and psoriatic arthritis. In spondyloarthritis (SpA), findings have not been uniform, with some studies reporting increased risks of Cesarean delivery, preterm birth, infants born small-for-gestational-age (SGA), and gestational diabetes- and hypertension, while others have failed to identify any significant differences between women with SpA and general population control women. Most studies reporting no differences have either been small or lacked an appropriate comparison group [1].ObjectivesTo assess the risk of adverse maternal and infant pregnancy outcomes in women with SpA compared to the general population.MethodsIn this nationwide register-based study, we included singleton births between April 2007 and December 2019 in women diagnosed with ankylosing spondylitis (AS; ICD-10 codes M45 or M08.1) or undifferentiated SpA (uSpA; ICD-10 codes M46.8 or M46.9). This was performed through linkage between the National Patient Register and the Medical Birth Register. Each birth was matched on birth year, maternal age, and parity to ten comparator births in women free from chronic inflammatory arthritis at time of birth. Relative risks (RR) of adverse outcomes were estimated by Poisson regression, adjusting for maternal country of birth, BMI, smoking in early pregnancy, educational level, and disposable income in the year before pregnancy.ResultsWomen with SpA (n=1394) were found to be at increased risk of several adverse outcomes compared to general population comparators (n=13932), as displayed in the Figure 1. Women with SpA had an increased risk of gestational diabetes (adjusted RR 1.88 [95% CI 1.10; 2.56]), elective and emergency Cesarean delivery (adjusted RR 1.54 [95% CI 1.32; 1.79] and 1.23 [95% CI 1.02; 1.48], respectively), and moderately preterm birth (adjusted RR 1.52 [95% CI 1.18; 1.97]). An association was seen with both spontaneous and medically indicated preterm birth, but the increase was only significant for spontaneous preterm birth. The risk estimate for preeclampsia was also increased, but failed to reach significance (adjusted RR 1.32 [95% CI 0.96; 1.81]). Infants to mothers with SpA were not more likely to be born SGA, but there was a slightly increased risk estimate of infection during their first year of life (adjusted RR 1.23 [95% CI 0.98; 1.53]).Figure 1.Number of events of adverse pregnancy outcomes among a nationwide cohort of births (n=1394) in Swedish women with SpA and comparator births (n=13932, matched 1:10 on birth year, maternal age, and parity). Relative risks from Poisson regression, adjusted for maternal country of birth, BMI, smoking in early pregnancy, educational level, and disposable income in the year before pregnancy.ConclusionWhile most pregnancies in women with SpA are uneventful, there is an increased risk for a number of adverse pregnancy outcomes. The increased risks for both emergency Cesarean delivery and spontaneous preterm birth suggest that these differences are not only driven by a different management of SpA pregnancies.