Incidence, Risk Factors and Outcomes of SARS‐CoV‐2 Infection in Pregnant Women: The COROPREG Population‐Based Study

International audience ; ABSTRACT Background Population‐based data are needed to reliably assess the impact of SARS‐CoV‐2 infection during pregnancy. Objectives To estimate the population‐based incidence of SARS‐CoV‐2 infection and its severe forms in the obstetric population, identify risk factors of severe SARS‐CoV‐2 infection (severe COVID‐19) and describe delivery, maternal and neonatal outcomes by disease severity, using a definition of severity based on organ dysfunction. Methods A prospective population‐based study conducted over the three first pandemic waves between March 2020 and April 2021 in 281 maternity hospitals in six French regions included all women with SARS‐CoV‐2 infection during pregnancy or within 7 days post‐partum, whether symptomatic or not, hospitalised or not. Severe COVID‐19 forms were defined a priori using clinical, biological and management criteria of organ dysfunction. We calculated infection and severe infection rates and studied associations between sociodemographic, medical and pregnancy characteristics and severe COVID‐19 by univariate and multivariate modified Poisson regression modelling. Results From a population of 385,214 deliveries in the participating regions, 6015 women with SARS‐CoV‐2 infection were identified, including 337 severe cases. The rates of severe COVID‐19 were 1.1, 0.9 and 3.6 per 1000 deliveries during the first, second and third pandemic waves, respectively, and the proportions of severe COVID‐19 were 8.6%, 3.4% and 9.3%, respectively. On multivariate analysis, the risk of severe COVID‐19 was associated with younger and older age, migrant status, living with > 4 people, overweight or obesity, chronic hypertension or diabetes and infection ≥ 22 weeks of gestation rather than earlier in pregnancy. Neonatal morbidity occurred mostly with severe maternal infection. Conclusion Using an organ‐based definition of severity and population‐based data, rates of severe COVID‐19 appeared lower than in previous studies. A permanent perinatal surveillance system is ...