Drug use in pregnancy and congenital anomalies: Sources of information in the East coast of Spain

Abstract Background Drug use (DU) during the first trimester of pregnancy (1tri) has been related to the development of some congenital anomalies (CA) The CA population-based Registry of Valencian Region (RPACCV) identifies DU from clinical records. Moreover, it exist the Dispensing drugs database to outpatient (GAIA). Aim to compare and identify differences between RPACCV and GAIA as sources for detect DU in CA's mothers during 1tri of gestation Methods Pregnant women, aged between 15-49 and residents in CV, which pregnancy outcome was a live birth or stillbirth with a CA between 2013-2021 were identified from RPACCV. Dispensed DU were obtained from GAIA and compared with the DU identified from RPACCV. In women which information was different between sources, DU were classified in: A, B, C, D, X based on the FDA Risk of use in pregnancy. Over-the-counter (OTC) were also identified. Proportions of DU based on the risk were estimated with their 95% confidence intervals (95%CI). Ratio for OTC was calculated by source Results 6818 women were identified, 3430 had DU registered in RPACCV and 3619 had DU in GAIA. Differences: 479 had DU registered in RPACCV with no dispensation in GAIA and 1463 women had DU in GAIA and no DU registered in RPACCV. DU with no risk for fetus (A/B) were the most found in both, being significantly higher in RPACCV 90% (95%CI:88-92) than in GAIA 84% (95%CI:83-86). However, DU of high risk for the fetus (C/D) or contraindicated (X) were mostly found in GAIA 16% (95%CI:14-17). OTC were recorded 7 times more in RPACCV. Moreover other DU as vaccines or methadone were not found in GAIA Conclusions To use RPACCV enables to obtain additional information as OTC, vaccines or methadone from medical records. Moreover, dispensations available from GAIA could identify more women with DU and more DU of high risk (C/D/X categories) in pregnancy. Therefore, to use both sources could be considered complementary and needed, as in synergy identify more women and more type of DU Key messages • In pregnancies with a congenital anomaly outcome in Valencian Region, most of drugs used during the first trimester had low risk for fetus and those of high risk were used under medical criteria. • Using multiple sources of information with drug use, such as population-based registries or dispensing data, allowed to identify more over-the-counter products and more pregnant women exposed.