Gestational diabetes mellitus and COVID-19: results from the CRONOS study

Gestational diabetes mellitus is one of the most frequent pregnancy complications with a global prevalence of 13.4% in 2021. Pregnant women with COVID-19 and gestational diabetes mellitus are 3.3 times more likely to be admitted to an intensive care unit compared to women without gestational diabetes mellitus. Data on the association of gestational diabetes mellitus with maternal and neonatal pregnancy outcomes in SARS-CoV-2-infected pregnant women are lacking. The aim of our study was to investigate whether gestational diabetes mellitus is an independent risk factor for adverse maternal and fetal/neonatal outcomes in pregnant women with COVID-19. CRONOS (COVID-19 Obstetric and Neonatal Outcome Study) is a registry-based multicentric prospective observational study from Germany and Linz/Austria. Pregnant women with clinically confirmed COVID-19 were enrolled between April 3, 2020 and August 24, 2021, at any stage of pregnancy. Obstetricians and neonatologists of 115 hospitals actively provided data to CRONOS. For collecting data a cloud based electronic data platform was developed. Women and neonates were followed until hospital discharge. Information on demographic characteristics, comorbidities, medical history, COVID-19 associated symptoms and treatments, pregnancy and birth outcomes were entered by the local sites. Information on the periconceptional body mass index was collected. A primary combined maternal endpoint was defined as (1) admission to an intensive care unit (including maternal mortality), and/or (2) viral pneumonia, and/or (3) oxygen supplementation. A primary combined fetal/neonatal endpoint was defined as (1) stillbirth >24+0 weeks of pregnancy, and/or (2) neonatal death