The EUROmediCAT network and databases: a resource for pharmacovigilance in pregnancy Short running title: The EUROmediCAT network and databases

The evidence gap relating to the risk of congenital anomalies (CA) associated with rst trimester medication exposure in pregnancy is well recognised. We describe the EUROmediCAT network and databases, and the methodological approach to pregnancy pharmacovigilance. Multidisciplinary expertise includes congenital anomaly diagnosis and epidemiology, pharmacoepidemiology, pharmacology and teratology. The EUROmediCAT central database comprises standardised data from 19 EUROCAT CA registries in 14 countries, including more than 40,000 CA cases 1995-2021 with rst trimester medication exposure data recorded, and a population coverage of 14.6 million births, growing by more than 650,000 births per year. The distributed database enables federated data analysis across eight countries which can link CA registries to electronic healthcare data, with population coverage of up to 917,000 births per year for linkage to maternal prescriptions, of which 315,000 births per year for linkage also to data on all births. The databases have enabled a variety of study designs: case-malformed control studies, cohort studies, disease cohort studies, signal detection studies, prevalence and ecological studies, and medication utilisation studies. A key strength is that studies of CA risk can address accurately the speci city of risk by type of CA. EUROmediCAT presents a unique data and expert resource for tackling the enormous evidence gap regarding the safety of medication during pregnancy.