Prescription medication use during pregnancy in France between 2010 and 2022: a nationwide study

Background: Exposure to medications during pregnancy is frequent, despite uncertainties about the impact on both mother and child health outcomes. In the era of growing use of large healthcare databases for pregnancy safety research, the mother-child register EPI-MERES was built from comprehensive data of the French National Health Data System (SNDS). Covering 98% of all deliveries in France since 2010, this powerful tool enables continuous surveillance of medication exposure during pregnancy, providing guidance on upcoming public health actions and research priorities.

Objectives: This nationwide study aimed to describe prevalence and time trends of prescription medication use during pregnancy in France, over the 13-year period between 2010 and 2022.

Methods: Using the EPI-MERES register, all pregnancies ending in a livebirth, a stillbirth or an elective/therapeutic abortion from 2010 to 2022 in mothers aged 12 to 55 years with at least one healthcare reimbursement in the year prior conception, were included. Medication use before, during and after pregnancy was assessed based on reimbursements data. Drugs considered as known teratogens were selected based on information from product labelling, available evidence from the literature and expert advice.

Results: A total of 11,599,431 pregnancies were included (9,101,062 ended in a livebirth, 42,016 in a stillbirth, 36,399 in a therapeutic abortion and 2,419,954 terminated before 22 weeks of pregnancy). For 9 out of 10 of them (90.5%), at least one prescription was filled during pregnancy. Over the study period, the number of different medications used during pregnancy decreased (from a median of 7 medications in 2010-2013 to 6 in 2020-2022) and the proportion of pregnancies exposed to at least one medication slightly declined from 92% to 89%.
Among livebirths, the top-5 therapeutic subgroups used during pregnancy were vitamins (67%), analgesics (65%), antianemic preparations (65%), drugs for functional gastrointestinal disorders (58%) and antibacterials for systemic use (40%). The use of omeprazole and vitamines increased between 2010 and 2022 (+100% and +43% respectively), whereas nasal, cough and cold preparations decreased by half.
Overall, 40,281 pregnancies (i.e. 0.35%) were exposed to at least one known teratogenic drug, of which 12,559 (31%) ended in a livebirth. Between 2010 and 2022, the prevalence of exposure to a known teratogenic drug during pregnancy decreased from 0.51% to 0.10%.

Conclusions: Despite slight decreases observed for few therapeutic subgroups, overall medication exposure among French pregnant women has remained high since 2010, including with regard to teratogenic drugs.