Pregnancy outcomes following maternal or paternal exposure to teriflunomide in the Danish MS population

Abstract

Background Teriflunomide (TFL) is an oral drug used for treatment of multiple sclerosis (MS). Due to possible teratogenicity it is contraindicated in women of childbearing potential. Additionally, a low risk of male-mediated embryo-fetal toxicity has been described as the drug can be transmitted via semen. This study investigated the association of adverse perinatal outcomes in newborns with either maternal or paternal exposure to TFL.Methods The Danish Multiple Sclerosis Registry was used to identify all patients treated with teriflunomide from 1st of September 2013 to 31st of December 2018. Data were merged with other nationwide national registries to identify all pregnancies with potential exposure to TFL. Exposure was defined as conception occurring after at least 30 consecutive days of treatment either during treatment or within two years of treatment discontinuation. Exposed pregnancies were matched 1:4 with controls from the general population. Individual outcomes of adverse perinatal events, namely preterm birth, congenital malformations, small for gestational age (SGA), stillbirth or low Apgar score were used to form a composite outcome, any adverse event, which was used for the analysis. Logistic regression was used to estimate the association of having any adverse event in newborns with either maternal or paternal exposure to TFL.Results A total of 112 TFL-exposed pregnancies were included of which 49 had maternal exposure and 63 paternal exposure. Among women, 21/49 pregnancies were terminated – 18 electively and three spontaneously. The remaining 28 pregnancies resulted in healthy newborns of which ≤3 were preterm. None of the newborns presented with malformations, being SGA or with low Apgar score. Among men, all 63 pregnancies resulted in birth of which 4/63 (6.3%) were preterm. Major malformations were registered in ≤3 event, and no newborn presented with low Apgar score or being SGA. No increased association of any adverse event was found in newborns with TFL exposure relative to controls (OR 1.03, 95% CI 0.50–2.13).Conclusion We did not find an increased prevalence of spontaneous abortion, preterm birth, congenital malformations, low Apgar score of being SGA in newborns with maternal or paternal exposure to TFL when compared with the general population. However, the sample was too small to draw firm conclusions.