Background: Exposure to medicines during pregnancy is frequent, even more during first trimester as pregnant women might not be aware of their condition. Aiming to establish potential relationship of earlier exposure to medicines and risk of abortion we conducted an observational study.
Methods: this is a retrospective case-control study of abortions (cases) and live birth pregnancies (controls) matched by mother age using SIDIAP database (Catalan Primary Health electronic health records database). Exposure to medicines while pregnant was considered to assess the risk of abortion during the first trimester. The odds ratio was estimated by a conditional logistic regression and adjust by health conditions and medicines exposures.
Results: A total of 60,350 episodes of abortions were matched to 118,085 live birth/completed pregnancy episodes. Cases had higher rates of alcohol intake (9.9% vs 7.2%), smoking (4.5% vs 3.6%) and of previous abortions (9.9% vs 7.8%). Anxiety (30.3% and 25.1%), respiratory diseases (10.6% and 9.2%) and migraine (8.2% and 7.3%), for cases and controls respectively, were the most frequent baseline conditions. Cases had higher rate of exposure to medicines [40,148 (66.5%) vs 37636 (68.9%), p<0.001, cases and controls respectively]. A risk for abortion was found for antihistamines for systemic use (ORadj 1.23, 95%CI 1.19-1.27), antidepressants (ORadj 1.11, 95%CI 1.06-1.17), anxiolytics (ORadj 1.31, 95%CI 1.26-1.73), and anti-inflammatory and rheumatic products, non-steroids (ORadj 1. 63, 95%CI 1.59-1.67).
Conclusions: These highest rate of medicines exposures during the first trimester of pregnancy and their relationship with abortion highlights the relevance of prescription to women with childbearing potential and may lead to better family planning information and contraception plans.
Registration: EUPAS37675