Baricitinib exposure during pregnancy in rheumatoid arthritis

We here describe the case of a 43-year-old White woman who was diagnosed with rheumatoid arthritis treated with anti-tumour necrosis factor drugs that caused an adverse drug reaction. The objective of this study was to describe the outcome of a pregnancy under baricitinib, a JAK-inhibitor drug, in a woman affected by rheumatoid arthritis. Scant data are available about the safety of JAK inhibitors during pregnancy. A case report and review of literature about JAK-inhibitor exposure during pregnancy were conducted. After the failure of biologic disease-modifying antirheumatic drugs due to a loss of efficacy and adverse drug reaction, the patient was started on baricitinib when it was marketed. During the fifth month of this treatment, she reported missing her period and a pregnancy was confirmed, despite a previous recommendation of adequate contraception. Thus, she had been exposed to baricitinib for several weeks before conception and during the whole first-trimester until the 17th week of gestation. The treatment with baricitinib was promptly discontinued and she was regularly examined. Foetal growth was normal throughout pregnancy and ultrasound examination did not detect any macroscopic abnormality. This is the first report of exposure to baricitinib during pregnancy outside the drug registration study program. We report the positive pregnancy outcome of a continuous exposure to baricitinib during the first 17 weeks of pregnancy. Small molecules, such as JAK inhibitors, are increasingly being used in clinical practice in rheumatoid arthritis and in other diseases. Hence, more broad and focused studies are required to have an insight of safety for this drug class in the case of accidental exposure before or during pregnancy.