Association Between COVID-19 Pandemic Phases and the Risk of Maternal Intensive Care Unit Admission: A Retrospective Analysis of 215,363 Victorian Hospital Admissions

Abstract

Background: There are no published Australian population-based data on serious COVID-19-associated maternal morbidity before and after widespread vaccination. Aims: To compare COVID-19 infection rates, intensive care unit (ICU) admissions, and length of stay in hospitalised pregnant patients before and after achieving 70% state-wide maternal COVID-19 vaccination coverage. Material and Methods: Population-based retrospective cohort study involving all hospital-admitted episodes for pregnant patients over 15-years-old with COVID-19 in Victoria from 1 March 2020 to 31 March 2022. Phase 1 was defined as March 2020—October 2021 when maternal vaccination coverage < 70%; Phase 2 was defined as Nove..