Background: The U.S. Food and Drug Administration under an Emergency Use Authorization approved use of Paxlovid (nirmatrelavir and ritonavir) for the treatment of mild-to-moderate COVID-19 in adults and children with a positive test for SARS-Co-2 and who are at high risk for progression to severe COVID-19. Pregnant women are at increased risk of severe complications resulting from COVID-19 infection; however, minimal data on the safety of Paxlovid in human pregnancy are available.
Objectives: The objectives of this study are to assess risks of major congenital malformations, spontaneous abortion, elective termination, stillbirth, preterm delivery, small for gestational age infants at birth, or infants who were small for age at one year in pregnancies/infants prenatally exposed to Paxlovid in pregnancy compared to individuals who did not receive this treatment.
Methods: This study involves prospective data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry which enrolls pregnant women residing in the U.S. or Canada and captures data through maternal interviews and abstraction of medical records.
Results: Among pregnant women participating in the OTIS Pregnancy Registry as of February 1, 2023, 59 reported exposure to Paxlovid in pregnancy; 25.4% exposed within 30 days prior to last menstrual period and through the first trimester, 42.4% exposed in second trimester, and 32.2% exposed in the third trimester. As of January, 2023, 17 of those enrolled have completed pregnancy outcomes. One was lost to follow-up. Of the remainder, there were no adverse pregnancy outcomes reported.
Conclusions: Very limited data are available on this potentially beneficial treatment in pregnancy. To date, no serious signals for this exposure have been detected.
