Preparedness for maternal and offspring health surveillance in pandemics: Lessons learned from studies on COVID-19 using Scandinavian registry data.

When the COVID-19 pandemic emerged, pregnant women were quickly identified as a high-risk group. It became a priority to clarify any risks associated with COVID-19 infection, and later vaccination, to pregnant women and their offspring. The Nordic registries constituted unique resources to quickly answer these questions. Our findings from the Nordic registries demonstrated that pregnant women with COVID-19 face a higher risk of hospitalization compared to non-pregnant women of reproductive age, and a higher risk of venous thromboembolism and stillbirth. However, the majority of studies proved no COVID-19 associated risks of adverse pregnancy outcomes. We also provided reassuring evidence indicating no increased risk of miscarriage, stillbirth, congenital malformations, preterm birth, or other adverse neonatal outcomes in children born to mothers vaccinated against COVID-19 during pregnancy. In this commentary, we highlight both opportunities and methodological challenges when using the Scandinavian health registries during an ongoing pandemic crisis.