No Teratogenic Signal Detected in Teriflunomide-Exposed Pregnancies

Current available data do not indicate a teratogenic signal in teriflunomide use during pregnancy in multiple sclerosis.

In women with multiple sclerosis, teriflunomide use during pregnancy does not appear to confer a teratogenic effect on a developing baby, according to an analysis of clinical trial and postmarketing data published in the Multiple Sclerosis Journal.

Researchers evaluated data from teriflunomide monotherapy phase 2 through 4 clinical trials and their extensions as well as postmarketing surveillance data to identify pregnancy outcomes among teriflunomide-treated women. A total of 222 pregnancies with confirmed teriflunomide exposure and known outcomes were included. Medical records were used to obtain clinical history and course data for each patient. The researchers also calculated estimated pregnancy duration and medication exposure. Outcomes of pregnancy that were examined in the study included live birth, spontaneous abortion, elective termination, ectopic pregnancy, and fetal death.

Related Articles

In the overall cohort, the researchers noted live births, elective abortions, spontaneous abortions, ectopic pregnancies, stillbirth, and maternal death leading to fetal death in 48.2%, 28.4%, 21.2%, 1.4%, 0.5%, and 0.5% of pregnancies, respectively. There were 4 birth defects in cases with known pregnancy outcome, including ureteropyeloectasia, congenital hydrocephalus, ventricular septal defect, and malformation of right foot valgus.

The study investigators noted 1 case of cystic hygroma in a case where the pregnancy outcome was unknown. The prenatal diagnosis of blighted ovum, a fetal anomaly, resulted in 1 elective abortion. In the clinical trials, the risk for major birth defects in live birth/stillbirth outcomes was 3.6%.

Limitations of the analysis include its retrospective design as well as the reliance on a small number of cases from postmarketing data.

“Further data collection will provide additional information on risks associated with teriflunomide exposure in pregnancy,” the researchers concluded. “To this end, the teriflunomide pregnancy registries are ongoing and routine postmarketing pharmacovigilance activities continue.”

Disclosure: This study was supported by Sanofi. Multiple authors disclosed affiliations with pharmaceutical companies including being employees of Sanofi with ownership interest. See the reference for complete disclosure information.


Vukusic S, Coyle PK, Jurgensen S, et al. Pregnancy outcomes in patients with multiple sclerosis treated with teriflunomide: clinical study data and 5 years of post-marketing experience [published online April 10, 2019]. Mult Scler. doi:10.1177/1352458519843055