Introduction SLE is an autoimmune disease with an increased risk for poor outcomes in pregnancy. In 2020, ACR specified several recommendations to assist clinicians in preparing patients with SLE and other rheumatic diseases for pregnancy management, with the intention of risk reduction for both the mother and developing fetus.¹ Two recommendations that are of particular importance in managing SLE pregnancies are to initiate low dose aspirin (LDA) and continuation of hydroxychloroquine (HCQ) therapy. We investigated whether the rate of adherence to these guidelines increased after their release at a single healthcare site.

Methods We identified all patients at Northwestern Medicine (NM) with 4 or more encounters billed for SLE, with at least one SLE encounter billed by a rheumatologist. Using diagnosis and procedure codes, we ascertained the approximate start and end dates of pregnancies that occurred following the first SLE diagnosis among these patients from 2012 to 2022. Next, we identified the presence of LDA if a medication order for low dose or baby aspirin occurred from 6 months prior to the beginning of pregnancy up to the end of the first trimester. The presence of HCQ therapy was determined by medication orders for HCQ occurring either 6 months before or during the pregnancy. The presence of antiphospholipid (APL) antibodies was determined if anti-cardiolipin, anti-beta-2-glycoprotein, or lupus anticoagulant were positive on two separate occasions 12 or more weeks apart. Finally, the number of pregnancies during which patients received specific ACR guidelines over the study period were summarized over time, before and after the start of 2020, and further delineated by patient APL status at the time of pregnancy.

Results We identified 529 pregnancies among people with SLE that occurred over the study period from 3,312 total female patients meeting our SLE identification algorithm. Overall, there was a general upward trend in the rates of patients receiving HCQ, LDA, or both over the study period (figure 1). The rates of pregnancies during which both LDA and HCQ were administered were 34% and 39% (p = 0.30) before 2020 and following the start of 2020, respectively (table 2). A larger, although non-significant, increase was also observed among patients with two different positive APLs, where the rate increased from 37% to 50% (p = 0.55) (table 1).

Discussion Our results suggest that there was only a modest, non-significant increase in implementing ACR guidelines for SLE in pregnancy in our health system following their release. Limitations include the single-center nature of the study and short follow-up period after implementation of the guidelines. It is anticipated that the recommended care will continue to increase as the guidelines are disseminated more widely. To obtain a sample with adequate size to study changes in prescribing patterns for pregnancy among patients with SLE in a broader context, future work will focus on implementation of our SLE and pregnancy identification strategies in a larger data network derived from multiple healthcare sites.

Reference

1. Sammaritano LR, Bermas BL, Chakravarty EE, Chambers C, Clowse MEB, Lockshin MD, et al. 2020 American College of Rheumatology Guideline for the Management of Reproductive Health in Rheumatic and Musculoskeletal Diseases. Arthritis Care & Research. 2020;72(4):461–88.

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Abstract 604 Figure 1

Use of ACR recommendations over time