Hydroxychloroquine treatment during pregnancy in lupus patients is associated with lower risk of preeclampsia

Background Hydroxychloroquine (HCQ) is regarded as a mainstay in the treatment of systemic lupus erythematosus (SLE) because of its efficacy in preventing flares, achieving remission, and reducing overall mortality. However, the impact of HCQ on pregnancy outcomes remains controversial. Objective We aimed to investigate the effect of HCQ on pregnancy outcomes in patients with SLE. Methods We performed a retrospective cohort study of 151 pregnancies in 122 patients with SLE (80 pregnancies in the HCQ treatment group and 71 pregnancies in the HCQ nontreatment group). We reviewed baseline characteristics including maternal comorbidities such as antiphospholipid syndrome, lupus nephritis, and autoimmune hepatitis. Pregnancy outcomes (preeclampsia, preterm delivery, and fetal growth restriction) and neonatal outcomes (gestational age at delivery and birth weight) were compared between HCQ treatment and nontreatment groups. Results Preeclampsia was significantly less complicated (7.5% vs 19.7%, p=0.032) and neonatal birth weight was significantly greater (2757.0583.5g vs 2542.3 +/- 908.3g, p=0.001) in the HCQ treatment group than in the HCQ nontreatment group. Multiple logistic analysis adjusting for body mass index (BMI), lupus nephritis, serum uric acid, and estimated glomerular filtration rate revealed HCQ treatment was associated with exceedingly lower risk of preeclampsia in SLE pregnancy (odds ratio (OR) 0.106 (confidence interval (CI) 0.017-0.671)). Other independent risk factors for preeclampsia were a high prepregnancy BMI (OR 1.575 (CI 1.114-2.227)) and low eGFR level (OR 0.931 (CI 0.886-0.979)) before pregnancy. Conclusion Our data showed pregnancy outcomes in SLE patients can be improved in the HCQ treatment group with about 90% reduction of preeclampsia.