Increasing rates of sars-cov-2 infection in newborns during the omicron variant epoch

Abstract

Problem: Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from infected pregnant individuals to the fetus or newborn occurs from 1.2% to 4.3%. Our aim was to determine the rate of positivity among newborns delivered to infected mothers during epochs of different variants predominance.

Method of study: This is a single academic center retrospective cohort study where we reviewed the electronic health records of pregnant individuals who tested positive for SARS-CoV-2 infection and their newborns from March 2020 through January 2022. Infants born to SARS-CoV-2-positive mothers at the time of delivery or within 10 days of admission were tested for SARS-CoV-2 infection at 24-36 h of age.

Results: A total of 195 mothers were positive at delivery or within 10 days of admission and had their newborns tested for SARS-CoV-2. Seven newborns (3.6%) were positive. All positive infants were asymptomatic and born to unvaccinated mothers. Newborn positivity for SARS-CoV-2 was highest during the Omicron epoch (9.4%, p = .01).

Conclusion: Increasing positivity rate was seen during the Omicron variant predominance. This could be attributed to postnatal acquisition of the virus, as Omicron has been associated with higher transmissibility in older children and adults.

Keywords: COVID-19; Omicron variant; newborn.