Pregnancy outcomes following maternal exposure to favipiravir: A Terafar case series

Objective

To assess pregnancy outcomes following maternal favipiravir exposure, with a particular focus on congenital malformations and neonatal development.

Methods

A case series, including data from pregnancies with favipiravir exposure between 2020 and 2021, was conducted at Izmir Katip Celebi University Teratology Information Center. Pregnant women and their infants were evaluated through structured interviews, ultrasonography, neonatal follow-ups, and developmental assessments. Congenital malformations were classified per EUROCAT criteria, and development was assessed using the Denver Developmental Screening Test-III.

Results

Of 45 pregnancies, 37 resulted in live births (including 1 set of twins), seven were electively terminated, and one ended in intrauterine death. Among the 28 infants with first-trimester exposure, 7.1 % (n = 2) had major malformations (congenital ichthyosis and hydronephrosis) and an additional 7.1 % (n = 2) had minor malformations (pleural effusion, patent foramen ovale). A review of exposure windows relative to critical developmental periods did not indicate a consistent or conclusive temporal association with the observed anomalies. Preterm birth and low birth weight rates were 9.6 % and 6.4 %, respectively. Neonatal jaundice occurred in 32.2 % of neonates. Developmental screening was normal in most cases, with one infant—who did not have any congenital malformations—exhibiting mild language delay.

Conclusion

Our study does not indicate a major teratogenic signal regarding favipiravir exposure in pregnancy, though the higher elective termination rate suggests increased risk perception. While study limitations prevent definitive conclusions, our findings may be of value to clinicians in counseling pregnant women regarding favipiravir exposure.