SARS-CoV-2 infection in pregnancy during the first wave of COVID-19 in the Netherlands: a prospective nationwide population-based cohort study (NethOSS).

Overtoom, Evelien M; Rosman, Ageeth N; Zwart, Joost J; Vogelvang, Tatjana E; Schaap, Timme P; van den Akker, Thomas; Bloemenkamp, Kitty W M

OBJECTIVE Describe characteristics, risk factors, maternal, obstetric and neonatal outcomes of SARS-CoV-2 infected pregnant women. DESIGN Multi-centre prospective population-based cohort study. SETTING Nationwide study in the Netherlands. POPULATION Pregnant women with confirmed SARS-CoV-2 infection admitted to hospital or in home-isolation: March 1st , 2020 - August 31st , 2020. METHODS Pregnant women with positive PCR or antibody tests were registered using the Netherlands Obstetrics Surveillance System (NethOSS). (Selective) testing occurred according to national guidelines. Data from the national birth registry (pregnant pre-COVID cohort) and an age-matched cohort of COVID positive women (National Institute for Public Health and the Environment; fertile age COVID cohort) were used as reference. MAIN OUTCOME MEASURES Incidence of SARS-CoV-2 infection in pregnant women. Maternal, obstetric and neonatal outcomes including hospital and intensive care admission. RESULTS Of 376 registered pregnant women with confirmed SARS-CoV-2 infection, 20% (74/376) were admitted to hospital, of whom 84% (62/74) due to SARS-CoV-2; 10% (6/62) were admitted to intensive care and 15% (9/62) to obstetric high care units. Risk factors for admission were non-European country of origin (OR 1.73, 95%CI 1.01-2.96) and being overweight/obese (OR 1.86, 95%CI 1.51-3.20). No maternal or perinatal deaths occurred. Caesarean section after labour-onset was increased (OR 1.58, 95%CI 1.09-2.28). Hospital and intensive care admission were higher compared to the fertile age COVID cohort (OR 6.75, 95%CI 5.18-8.81 and OR 2.52, 95%CI 1.11-5.77 respectively). CONCLUSIONS Non-European country of origin and being overweight/obese are risk factors for severe course of SARS-CoV-2 infection in pregnancy, risk of caesarean section and hospital and ICU admission are increased.