LATEBREAKER
Infectious Disease
Neonatal outcomes among people vaccinated against COVID-19 during pregnancy in the United States, December 2020-September 2022 Stacey L Rowe* Stacey L Rowe Annette K Regan Sheena G Sullivan Flor Munoz Jennifer Griffith Matthew Coates Onyebuchi A. Arah
Background: Vaccination against COVID-19 is recommended during pregnancy to protect pregnant people and infants against severe disease. Whilst the safety of COVID-19 vaccination during pregnancy is well-established, there is limited evidence on the incidence of congenital abnormalities among infants born to vaccinees.
Methods: We assembled a national cohort of pregnancies ending 11 December 2020–30 September 2022 using Merative™ Marketscan® Commercial & Medicaid Databases. COVID-19 vaccines were identified from outpatient and inpatient drug records. Neonatal outcomes were identified from hospital inpatient encounters, and included: major structural birth defects; microcephaly and other congenital abnormalities including ankyloglossia (tongue-tie). Incidence of neonatal outcomes was calculated by insurance type (public versus private). Associations between maternal COVID-19 vaccination and outcomes were estimated using Poisson regression.
Results: We identified 550,590 pregnancies ending in livebirth, of which 14.3% were vaccinated during pregnancy. 5,448 (1%) infants born to vaccinated individuals had a major structural birth defect and 1,203 (<1%) had microcephaly. There were no variations in the incidence of these conditions by insurance type; however, incidence of ankyloglossia was higher among privately-insured people (5.4% versus 2.8%). COVID-19 vaccination during pregnancy was associated with ankyloglossia in the privately-insured cohort (aIRR 1.20; 95% CI 1.16, 1.25) but not in the publicly-insured cohort (aIRR 0.72; 95% CI 0.65, 0.79). Insurance type was identified as an effect modifier.
Discussion: Monitoring neonatal outcomes is an important element of maternal vaccine program evaluation. Previous studies have suggested that maternal vaccination is associated with ankyloglossia. Our findings demonstrate that this effect is modified by insurance type, indicating that previously reported associations may be influenced by residual/uncontrolled confounding.