Approximately 26% of women with inactive or mild lupus at conception experienced flares at some point during pregnancy, based on data from 384 patients.
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Active systemic lupus erythematosus (SLE) is a known predictor of poor pregnancy outcomes, including preterm birth, growth restriction, and fetal loss, but predictors of flares during and after pregnancy in women with SLE have not been well studied, wrote Julia Davis-Porada, MD, of the Hospital for Special Surgery, New York, and her colleagues.
In a study published in Arthritis Research & Therapy, the investigators reviewed data from the PROMISSE (Predictors of Pregnancy Outcome: Biomarkers in Antiphospholipid Antibody Syndrome and Systemic Lupus Erythematosus) study, a prospective study of pregnant women aged 18-45 years. The women were enrolled at less than 12 weeks’ gestation, and participants had a baseline hematocrit greater than 26%. Participants met criteria for inactive or mild/stable disease at the time of conception.
Overall, 20.8% of patients experienced at least one mild or moderate flare and 6.25% had one or more severe flares during pregnancy. Mild to moderate flares and severe flares occurred postpartum (2-6 months after the end of pregnancy) in 22.7% and 1.7% of patients, respectively.
Patients who were younger and those who had lower C4 at baseline and higher Physician Global Assessment scores at baseline were significantly more likely to have at least one flare during pregnancy (P = .003, P = .024, P = .0005, respectively).
In the analysis of postpartum flares, the incidence rates for mild to moderate and severe flares were 0.8 and 0.06 per person-year, respectively. “In contrast to the findings observed for flares that occurred during pregnancy, baseline patient characteristics were not correlated with postpartum flares,” the researchers wrote.
No medications were associated with flares during or after pregnancy.
The study findings were limited by several factors, including the exclusion of SLE patients with current nephritis and those who needed high-dose prednisone; the potential for missed flares; and the lack of postpartum data for approximately 10% of patients, the researchers noted. Also, “since many patients presented to this study only after conception, we have no data to review disease activity prior to pregnancy to determine whether pregnancy per se increased the risk for flare,” they said.
However, the results were strengthened by the large, multiethnic population and prospective study design, and support physicians in reassuring patients with SLE that pregnancy and postpartum flares are unlikely if they plan pregnancy during a time of mild or inactive disease, they concluded.
The study was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The researchers had no financial conflicts to disclose.
SOURCE: Davis-Porada J et al. Arthritis Res Ther. 2020 Mar 19. doi: 10.1186/s13075-020-2139-9.