Deshayne B Fell, Sheryll Dimanlig-Cruz, Eszter Török, Siri E Håberg, Annette K Regan, Jay S Kaufman, Robert W Platt, Christopher A Gravel, Liam Bruce, Prakesh S Shah, Kumanan Wilson, Ann E Sprague, Gillian D Alton, Tavleen Dhinsa, Darine El-Chaâr, Sarah A Buchan, Jeffrey C Kwong, Sarah E Wilson, Sandra I Dunn, Shannon E MacDonald, Jon Barrett, Nannette Okun, Mark C Walker
OBJECTIVE: To assess risk of adverse pregnancy, fetal, and neonatal outcomes after a third dose (first booster dose) of covid-19 vaccine during pregnancy among individuals who had completed both doses of primary covid-19 vaccine series before pregnancy. DESIGN: Population based, retrospective cohort study. SETTING: Ontario, Canada, from 20 December 2021 to 31 August 2022. PARTICIPANTS: Individuals were included if they were pregnant with an expected date of delivery from 20 December 2021 (start date of third dose eligibility for everyone ≥18 years) to 31 August 2022, who had completed the two doses of primary covid-19 messenger RNA vaccine series before pregnancy, and became eligible for a third dose (≥six months since dose two) before the end of pregnancy...
2023: BMJ Med