SUBOPTIMAL MEDICATION USE AND WORSE PERIPARTUM OUTCOMES IN WOMEN WITH LUPUS COMPARED TO THE GENERAL POPULATION

O064 / #405 Topic: AS21 - Pregnancy and Reproductive Health ABSTRACT CONCURRENT SESSION 11: PREGNANCY IN SLE 24-05-2025 10:40 AM - 11:40 AM Background/Purpose Observational and population levels studies confirm that systemic lupus erythematous (SLE) is associated with worse maternal and neonatal outcomes by way of disease activity and peripartum treatment choices compared to the general population without immune-mediated inflammatory diseases (IMID).[1] Increasingly, international societies have modifed their recommendations for peripartum medication use and have recognized the general safety of medications such as hydroxychloroquine and azathioprine throughout pregnancy.[2] We hypothesize that despite increased availability of safe peripartum disease treatments for SLE, outcomes are still worse and treatments underutilized compared to those without IMID in a contemporary Albertan pregnancy cohort. Methods A contemporary pregnancy cohort of 446,017 women and corresponding birth events was assembled for the province of Alberta, Canada from the random selection of 1 live birth event per woman between Jan 1st, 2009 and December 31, 2023. We identified one group with no IMID (n=728,102) and one group with SLE (n=393) using ICD 9 and 10 codes and excluding mothers in the “no IMID” group with any dispensation of corticosteroids for 4 weeks or more during pregnancy. We compared maternal and neonatal outcomes, comorbid conditions and medication use at any point in the pregnancies among the 2 groups. Anatomical Therapeutic Chemical Classification System (ATC codes) were used to identify medication use during the 270 days prior to delivery. Results More SLE mothers (22.1%) were > 35 years old compared to 15.2% of no IMID mothers. Emergent and elective cesarean section deliveries were higher in women with SLE compared to those no IMID. Women with SLE were more likely to have preterm delivery (13.7%), “small for gestational age” babies (19.3%), and NICU admissions (18.6%), compared to those without IMID (Table 1). Medication use among SLE mothers at any point in the pregnancy included 12.5% on glucocorticoids, 3.6% on nonsteroidal antiinflammatories, 25.4% on antimalarials, 3.6% on nonbiologic disease modifying antirheumatic drugs and 1.3% on biologic DMARDs. No women had exposure to anifrolumab or belimumab. Table 1. Maternal Characteristics and Peripartum Outcomes Conclusions Women with SLE have worse peripartum outcomes compared to those without IMIDs. Medications such as antimalarials which are safe in pregnancy are underutilized which may influence these outcomes. Further peripartum studies in this population are needed to evaluate drug uptake and safety over time and whether guidelines are impacting how clinicians manage these complex patients. References: [1.] Tan Y. J Autoimmun 2022;132:102864. [2.] Russell M. Rheumatol (Oxford) 2023;62(4):1370-87.