Prescription drug use during pregnancy: a population-based study in Regione Emilia-Romagna, Italy

Purpose Drug utilization studies in pregnant women are crucial to inform pharmacovigilance efforts in human teratogenicity. The purpose of this study was to estimate the prevalence of prescription drug use among pregnant women in Regione Emilia-Romagna (RER), Italy. Methods We conducted a retrospective prevalence study using data from the RER health care database. Outpatient prescription drug data were reconciled for RER residents who delivered a baby in a hospital between January 1, 2004 and December 31, 2004. Drug data were stratified by trimester of use, pregnancy risk categorization, and anatomical classification. Results Among the 33,343 deliveries identified in 2004, 70% of women were exposed to at least one prescription medication during pregnancy and 48% were exposed to at least one prescription medication after excluding vitamin and mineral products. Many of the most commonly used medications were anti-infectives, such as amoxicillin, fosfomycin, and ampicillin. Nearly 1% of women were exposed to drugs contraindicated (i.e., category X) in pregnancy, including 189 women (0.6%) who received these drugs during the first trimester. Several statin medications were among the most common contraindicated drug exposures. Conclusion A large proportion of women who gave birth in RER in 2004 were exposed to prescription medications. Approximately 1 in 100 women were exposed to contraindicated drugs. The most commonly identified drug exposures can help focus pharmacoepidemiologic efforts in drug-induced birth defects.