Drug exposure characteristics and related pregnancy outcomes in pregnant women: an observational cohort study

<b>Aims/Background</b> The relationship between drug exposure and pregnancy outcomes is still unclear. The study was designed to characterise the overall condition of drug exposure during pregnancy and uncover related pregnancy outcomes. <b>Methods</b> Pregnant women were enrolled in the study from 1 October 2019 to 31 April 2022, at a tertiary hospital in Jiangsu Province, China. Basic maternal information and data regarding drug exposure during different pregnancy trimesters were gathered using the 'Eugenic Baby' platform. Based on drug use data and the pregnancy and lactation labelling rule, pregnant women were divided into three groups to explore the relationship between drug exposure and pregnancy outcomes. <b>Results</b> Analysis revealed that fetal protection drugs were used in 43.99% of early pregnancy cases. Pregnant women utilised more unrecommended drugs (according to the pregnancy and lactation labelling rule) in the first trimester than in the following trimesters. Regarding pregnancy outcomes, 56 of the 837 live infants had a malformation, and congenital heart disease was the main type. Gestational age, mode of delivery, birth weight, height, and head circumference were significantly different (<i>p</i> < 0.05) among the three groups. According to multivariate logistic regression analysis, preterm birth (odds ratio=3.226, 95% confidence intervals: 1.447-7.194, <i>p</i>=0.004) and low birth weight (odds ratio=4.270, 95% confidence intervals: 1.299-14.034, <i>p</i>=0.017) predicted increased risk of maternal drug exposure after adjusting for covariates. <b>Conclusion</b> Drug exposure of various types is common during pregnancy. Compared to the second and third trimester, unrecommended drugs are used more frequently in the first trimester. Drug exposure is associated with adverse pregnancy outcomes and these associations need to be further confirmed. It is vital to fully consider treatment benefits and potential risks before medication initiation during pregnancy.