Women with systemic lupus erythematosus have a two-fold increase in risk of preeclampsia, according to a study of disease-modifying antirheumatic drugs in pregnant women.
Use of DMARDs during pregnancy was rare in the study population, but women who used the medications showed an increase in preeclampsia risk. The increase was not statistically significant and could be explained by the severity of autoimmune disease among DMARD users, the researchers said. DMARDs include methotrexate (Rheumatrex, Trexall), anti-malarial drugs such as hydroxycholorquine (Plaquenil) and biologics such as etanercept (Enbrel) or adalimumab (Humira).
To compare risk of preeclampsia in DMARD users, researchers with the Harvard School of Public Health used the British Columbia healthcare utilization database to identify 306,831 pregnancies in 224,827 women with and without autoimmune disease. Women who filled a prescription for DMARDs, non-steroidal anti-inflammatory drugs or corticosteroids before pregnancy were considered “past users,” and those who filled these prescriptions both before and during the first 20 weeks of pregnancy were designated “continuous users.”
Pregnant women in the study had a median age of 30, with 0.3% of women diagnosed with RA or psoriasis, 0.2% with inflammatory bowel disease, 0.1% with SLE and another 0.1% with multiple sclerosis. Within this cohort, researchers found that 1,226 women (0.4%) used a DMARD in the year before pregnancy, while only 414 (0.1%) used DMARDs while pregnant. The occurrence of preeclampsia in past DMARD, steroid and NSAIDs users was 2.3%, 2.7% and 2.9%, respectively.
Compared with women who did not have autoimmune disease, women with SLE had twice the risk of preeclampsia during their pregnancy year. Further analysis indicated that a continuous DMARD user was at greater — though not statistically significant — risk of preeclampsia compared with past DMARD users. Restricting the analysis to women with autoimmune diseases weakened the relative risk of preeclampsia in DMARD users.
That reduction in relative risk suggests “that the underlying disease or severity of the disease was likely contributing to the increased risk of preeclampsia among DMARD users,” Kristin Palmsten, the studys lead author and a doctoral student at HSPH, said in a news release. Further studies are needed to confirm the findings, the authors said, and research should focus on DMARD use and preeclampsia in women with specific autoimmune diseases.
The study appears in the November issue of Arthritis Care & Research, a journal of the American College of Rheumatology. The study abstract is available at http://onlinelibrary.wiley.com/doi/10.1002/acr.21807/abstract.