Drug Exposure During Pregnancy : A Case-Control Study from a Primary Care Database

Objective: Drug exposure during pregnancy is frequent, even more during first trimester as pregnant women might not be aware of their condition. We used available electronic health records (EHRs) to describe the use of medications during the first trimester in pregnant women and to compare drug exposure between those women who had an abortion (either elective or spontaneous) compared to those who had live births. Materials and Methods: Case-control study of abortions, either elective or spontaneous (cases), and live birth pregnancies (controls) in Sistema d'Informació per al Desenvolupament de la Investigació en Atenció Primària (Catalan Primary Health electronic health records) from 2012 to 2020. Exposure to drugs during first trimester of pregnancy was considered to estimate the association with abortion by conditional logistic regression and adjusted by health conditions and other drugs exposure. Results: Sixty thousand three hundred fifty episodes of abortions were matched to 118,085 live birth pregnancy episodes. Cases had higher rates of alcohol intake (9.9% vs. 7.2%, p < 0.001), smoking (4.5% vs. 3.6%, p < 0.001), and previous abortions (9.9% vs. 7.8%, p < 0.001). Anxiety (30.3% and 25.1%, p < 0.001), respiratory diseases (10.6% and 9.2%, p < 0.001), and migraine (8.2% and 7.3%, p < 0.001), for cases and controls, respectively, were the most frequent baseline conditions. Cases had lower rate of drug exposure, 40,148 (66.5%) versus 80,449 (68.1%), p < 0.001. Association with abortion was found for systemic antihistamines (adjusted odds ratio [OR] 1.23, 95% confidence interval [CI] 1.19-1.27), antidepressants (OR 1.11, 95% CI 1.06-1.17), anxiolytics (OR 1.31, 95% CI 1.26-1.73), and nonsteroidal anti-inflammatory drugs (OR 1. 63, 95% CI 1.59-1.67). Conclusions: These high rates of drug exposures during the first trimester of pregnancy highlights the relevance of informed prescription to women with childbearing potential.