Patterns of Prescription Medication Use during the First Trimester of Pregnancy in the United States, 1997-2018

Abstract

The objective of this analysis was to describe patterns of prescription medication use during pregnancy, including secular trends, with consideration of indication, and distributions of use within demographic subgroups. We conducted a descriptive secondary analysis using data from 9,755 women whose infants served as controls in two large United States case-control studies from 1997-2011 and 2014-2018. After excluding vitamin, herbal, mineral, vaccine, i.v. fluid, and topical products and over-the-counter medications, the proportion of women that reported taking at least one prescription medication in the first trimester increased over the study years, from 37% to 50% of women. The corresponding proportions increased with increasing maternal age and years of education, were highest for non-Hispanic White women (47%) and lowest for Hispanic women (24%). The most common indication for first trimester use of a medication was infection (12-15%). Increases were observed across the years for medications used for indications related to nausea/vomiting, depression/anxiety, infertility, thyroid disease, diabetes, and epilepsy. The largest relative increase in use among women was observed for medications to treat nausea/vomiting, which increased from 3.8% in the earliest years of the study (1997-2001) to 14.8% in 2014-2018, driven in large part by ondansetron use. Prescription medication use in the first trimester of pregnancy is common and increasing. Many medical conditions require treatments among pregnant women, often involving pharmacotherapy, which necessitates consideration of the risk and safety profiles for both mother and fetus.

Figure 1

Prescription medication use in first trimester*, National Birth Defects Prevention Study (1997–2011) and Birth Defects Study to Evaluate Pregnancy Exposures (2014–2018). (a) Percent taking >1 medication (error bars indicate 95% confidence intervals). (b) Average number of prescription medications taken (error bars indicate 95% confidence intervals). *First trimester, 30 days before to 90 days after pregnancy onset.

Figure 2

Prescription medication use in first trimester* over time, National Birth Defects Prevention Study (1997–2011) and Birth Defects Study to Evaluate Pregnancy Exposures (2014–2018). (a) Anti-infective medication use. (b) Anti-nausea/vomiting medication use. (c) Antidepressant/anxiety medication use. (d) Fertility medication use. (e) Thyroid and anti-diabetic medication. * All reported use, including non-thyroid indications. ** All reported use, including non-diabetic medications. (f) Anti-convulsant medication use, including non-seizure indications. (g) Opioid medication use. *First trimester, 30 days before to 90 days after pregnancy onset. (Error bars represent 95% confidence intervals.)