OA06 Pregnancy as a cardiometabolic stress test in rheumatoid arthritis: outcomes and the impact of biologic therapy

Abstract Background/Aims RA is associated with increased cardiometabolic risk and an increased risk of adverse pregnancy outcomes. Although the absolute risk of cardiometabolic disease is low in females of childbearing age, pregnancy functions as a physiological “stress test” that can unmask subclinical vulnerabilities—such as gestational diabetes (GDM), pre-eclampsia, and small-for-gestational-age (SGA) infants (10th centile)—which predict future maternal cardiometabolic health. Methods Females with RA (ACR/EULAR 2010) delivering at our centre between January 2019 and September 2025 were identified via the electronic health record and matched 1:1 by age with healthy controls (HC). Ethical approval was granted by the University College London Hospitals Data Trust Committee (IRAS ID: 299136). Results Seventy-five pregnancies in 67 women with RA and 75 age-matched controls (median age 36) were analysed (Table 1). Groups were similar in parity, BMI, and pre-existing cardiometabolic disease; a minority of RA patients were current smokers. RA pregnancies were almost three times more likely to receive aspirin for preterm pre-eclampsia prophylaxis. RA patients showed a threefold higher rate of preterm birth and a modestly higher rate of SGA, but were slightly less likely to develop pre-eclampsia or GDM. None of these differences reached statistical significance (p 0.05). RA pregnancies were further categorised by medication exposure: no treatment, csDMARD only, and biologic DMARD (bDMARD) use. Outcomes were most favourable among bDMARD users—none developed pre-eclampsia or delivered preterm, and they had the lowest rates of SGA. Although 10.5% (n = 2) developed GDM among bDMARD users, both had discontinued bDMARD therapy during pregnancy. Conclusion Overall, pregnancy outcomes in RA were comparable to healthy controls. However, approximately one in ten RA pregnancies was complicated by GDM or preterm birth, and one in five infants was SGA—markers that, in the general population, predict elevated future cardiometabolic risk. Whether these pregnancy-related risk signals translate similarly in RA requires longitudinal study. Notably, those maintaining bDMARD therapy had the most favourable outcomes, suggesting that effective inflammatory control during pregnancy may mitigate both obstetric and future cardiometabolic risk. Disclosure B. Goulden: Other; speakers fees for a talk for GSK. T. Mitra: None. G. Woodward: None. I. Giles: Grants/research support; Unrestricted research grants from Union Chimique Belge (UCB). Other; BSR - unpaid lead of working group that produced guidelines on prescribing in pregnancy. D. Nzelu: None.