Favorable pregnancy outcomes in two patients with systemic lupus erythematosus treated with belimumab

Background Systemic lupus erythematosus (SLE) is associated with poor pregnancy outcomes and complications. Belimumab can significantly improve disease activity in patients with SLE. However, there is insufficient evidence to prove the absolute safety of belimumab treatment during pregnancy. Case Summary A 37-year-old woman was diagnosed with SLE after a renal puncture biopsy in 2012. The other patient was a 25-year-old woman. She was diagnosed with SLE at 19 years of age. They were treated by standard therapy in the early stage of treatment. The first patient has multiple histories of miscarriages or abortions at different gestational ages caused by SLE activity. The other patient also has persistent thrombocytopenia due to SLE flare. In our patients, SLE was poorly controlled by standard therapy. We initiated belimumab treatment during pregnancy because the benefits of treating SLE outweighed the risks to the fetus. The first patient was admitted to the first belimumab infusion at approximately 14 weeks of gestation. The other patient was admitted to the first belimumab infusion at approximately 12 weeks of gestation. Although our patients did not show complete disease remission during belimumab treatment, neither had serious adverse reactions or adverse pregnancy events, and their babies were in good conditions at birth. Conclusion We present 2 cases of pregnant women with SLE who were treated with belimumab. Both were able to deliver their babies successfully without any complications.