The outcomes of favipiravir exposure in pregnancy: a case series

Purpose As in vitro and in vivo studies reported antiviral efficacy against RNA viruses, favipiravir, a pyrazinecarboxamide derivative, has become one of the treatment options for COVID-19 in some countries including Turkey. Preclinical studies demonstrated the risk for teratogenicity and embryotoxicity. Hence, the drug is contraindicated during pregnancy. Although limited in numbers, case-based evaluations indicate that favipiravir might not be a major teratogen in human pregnancies. This study aimed to present and analyze the outcomes of favipiravir exposure during pregnancy. Methods In this case series, the outcomes of nine pregnancies that were referred to the Teratology Information Service of Dokuz Eylul University Faculty of Medicine, Department of Medical Pharmacology between 01 April 2020 and 30 November 2021 were retrospectively evaluated. Results One spontaneous abortion, two elective terminations, one preterm live delivery and five term live deliveries were detected. The premature newborn was reported dead on the 5th day of neonatal intensive care unit admission. Physiological jaundice and transient respiratory distress were recorded in two term infants. One term infant was antenatally diagnosed with renal pelviectasis, but the findings resolved postnatally without requiring intervention. Conclusion The data indicate that favipiravir is not likely to be a major teratogen. Yet, it is not possible to draw a definite conclusion due to methodological limitations. Favipiravir exposures during pregnancy should be followed up closely and the outcomes should be reported consistently.