(077) Updated Real-World Safety of the Pfizer-BioNTech COVID-19 Vaccine in Pregnancy: Data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry
Background: Preliminary data indicate that pregnant women infected with COVID-19 are at increased risk of pregnancy complications (US Centers for Disease Control and Prevention, October, 2022). Information on the real-world safety of COVID-19 vaccination in pregnancy is essential.
Objectives: To describe preliminary results for pregnancy status among pregnancy registry participants enrolled in an ongoing safety study of the Pfizer-BioNTech COVID-19 vaccine to date.
Methods: This study uses data from the Organization of Teratology Information Specialists (OTIS) Pregnancy Registry as part of the Vaccines and Medications in Pregnancy Surveillance System (VAMPSS) which enrolls pregnant women residing in the US or Canada. Data on exposures, outcomes and covariates are captured through maternal interviews and abstraction of medical records. The study population for this descriptive analysis includes Registry participants who met eligibility criteria on or after December 11, 2020, the date the US Food and Drug Administration granted emergency-use authorization for the Pfizer-BioNTech vaccine. The target sample size is 1,100 pregnant women who received any dose of the Pfizer-BioNTech vaccine from 30 days prior to the last menstrual period through the end of pregnancy, and 900 comparison women who received no COVID-19 vaccine in pregnancy.
Results: Among pregnant women participating in the Registry between 11 December 2020 and 22 July 2022, 1,100/1,100 participants (100.0% of the target sample) were enrolled as part of the Pfizer-BioNTech COVID-19 vaccine exposure cohort, and 635/900 participants (70.6% of the target sample) were enrolled in the comparator cohort. As of 22 July 2022, 858 (78.0%) in the vaccine exposure cohort and 313 (34.8%) in the comparator cohort had completed pregnancies.
Descriptive data indicated numerically similar percentages of pregnancies ending in at least one liveborn infant, spontaneous abortions, stillbirths, and elective terminations across the exposed cohort stratified by trimester of the earliest dose of the Pfizer-BioNTech COVID-19 vaccine received in pregnancy, and overall in the unexposed comparator cohort (Table).
Conclusions: Preliminary data have not identified any new safety concerns thus far for pregnant women who receive the Pfizer-BioNTech COVID-19 vaccine during pregnancy.
