Pregnancy outcomes in patients with multiple sclerosis treated with teriflunomide: Clinical study data and 5 years of post-marketing experience

Background: Teriflunomide is contraindicated in pregnancy. Some pregnancies have occurred despite guidance to use effective contraception. Objectives: To report outcomes of pregnancies occurring in teriflunomide clinical trials and the post-marketing setting. Methods: Outcomes are summarized for pregnancies in teriflunomide monotherapy clinical trials and the post-marketing setting (data cutoff: December 2017). Results: Of 437 confirmed teriflunomide-exposed pregnancies, 222 had known outcomes (70 from clinical trials; 152 from the post-marketing setting); 161 were reported prospectively and 61 retrospectively. There were 107 (48.2%) live births, 63 (28.4%) elective abortions, 47 (21.2%) spontaneous abortions, 3 (1.4%) ectopic pregnancies, 1 (0.5%) stillbirth, and 1 (0.5%) maternal death leading to fetal death. Four birth defects were reported among cases with known pregnancy outcome: ureteropyeloectasia (only defect considered major); congenital hydrocephalus; ventricular septal defect; and malformation of right foot valgus. A case of cystic hygroma was identified on antenatal ultrasound (pregnancy outcome unknown). One elective abortion followed prenatal diagnosis of fetal anomaly (blighted ovum). The risk of major birth defects in prospectively reported live birth/stillbirth outcomes was 3.6% (1/28) in clinical trials and 0.0% (0/51) in post-marketing reports. Conclusions: Outcomes were consistent with the general population. Current human data do not indicate a teratogenic signal in teriflunomide-exposed pregnancies.