Research on Medicines and Pregnancy

Group of scientists studying health data

CDC and partners study medicine use in pregnancy to understand how specific medicines might affect the pregnancy. Results of these studies give women and healthcare professionals better information on the safety and risks of using specific medicines before, during, and after pregnancy. This information supports their ability to weigh the risks and benefits of medicines together and make decisions about treatment options based on the best available information.

Is YouTube Info Accurate?

In a recent study, CDC researchers found that current YouTube videos that discuss the safety of using medicines during pregnancy do not often give scientifically accurate information on specific medicines.

Read the key findings

Medicine Use during Pregnancy

CDC research shows that taking medicines during pregnancy is common and increasing over time.

  • Almost 1 in 4 pregnant women and nearly half of non-pregnant women between 15–44 years of age reported using prescription medicines in the last 30 days.
  • About 9 in 10 women take at least one medicine during pregnancy, and 7 in 10 take at least one prescription medicine.

Most commonly used medicines in the first trimester

In a 2013 study, researchers identified the medicines most commonly used by women during the first trimester (first 3 months) of pregnancy, listed below.

Prescription Medicines
Prescription medication bottle

Birth control pills
A medicine to prevent pregnancy

A medicine to treat infections

A hormone to treat many conditions

A medicine to help control asthma

A medicine to help with allergies or nausea

Over-the-Counter Medicines
Over the counter medicine bottle

A medicine to help with pain – Brand name: Tylenol®

A medicine to help with pain – Brand name: Advil®, Motrin®

A medicine to soften stool

A medicine to treat cold symptoms

A medicine used to treat many conditions, including pain

A medicine to help with pain – Brand name: Aleve®

How CDC Studies Medicine Use in Pregnancy

We know little about the effects of taking most medicines in pregnancy, because pregnant women are often not included in studies that determine the safety of new medicines. However, listed below are a few ways CDC works to find out more about the effects a medicine might have when taken during pregnancy.

Dr. Jennifer Lind Video Screen Shot

Watch Dr. Jennifer Lind, a CDC pharmacist, talk about a study that examined outpatient prescriptions filled for opioid medicines (used to treat pain) from a group of reproductive-aged women with public or private insurance in the United States. Medscape allows free unlimited access to materials after registration.

Studies from the Centers for Birth Defects Research and Prevention

CDC funds the Centers for Birth Defects Research and Prevention, which partners on large studies, such as the National Birth Defects Prevention Studyexternal icon (births 1997-2011) and the Birth Defects Study to Evaluate Pregnancy exposureS (BD-STEPS) (2014-present). These studies work to

  • Identify factors that may increase the risk for birth defects and
  • Answer questions about medicines taken during pregnancy.

Adverse event reports

Drug companies are required to report problems with medicines to the FDA. Healthcare professionals, researchers, and the public, including pregnant women, can report suspected problems directly to the FDA MedWatch Programexternal icon.

Pregnancy registries

Pregnancy registries are systems for tracking outcomes in pregnant women who take a particular medicine.  After these women give birth, researchers compare the health of their babies to the health of the babies of women who did not take the medicine. Pregnancy registries are a useful way to study the effects of a particular medicine and gather health information during pregnancy and after delivery. For a list of current pregnancy registries and how to enroll in them, visit the FDA Pregnancy Registry websiteexternal icon.

Are you a healthcare professional?

You play an important role in reviewing safety information and making shared decisions with women about treatments before, during, and after pregnancy. Remember, you might be “treating for two.”

  • Before prescribing medicines to a woman of reproductive age, ask her if she is pregnant or thinking of becoming pregnant. If she is not planning a pregnancy, discuss effective birth control options.
  • Discuss current medicines with patients, especially women who are newly pregnant, those who are planning a pregnancy, and those who could become pregnant during the course of treatment. Include prescription and over-the-counter medicines, as well as vitamins, supplements, and dietary or herbal products in your discussion.
  • Work with your patients to ensure that they are taking only what is necessary.
  • Emphasize to patients that sharing their own or borrowing prescription medicines from others could harm them or their developing baby.

Suggested Reading

Below are articles that provide a brief history and current discussion on medicine use in pregnancy. The articles are in order of date published.

Making Decisions About Medication Use During Pregnancy: Implications for Communication Strategies.
Matern Child Health J. 2018; 22(1): 92-100.
Lynch MM, Squiers LB, Kosa KM, Dolina S, Read JG, Broussard CS, Frey MT, Polen KN, Lind JN, Gilboa SM, Biermann J.
[Read article]external icon

Medications in the first trimester of pregnancy: most common exposures and critical gaps in understanding fetal risk
Pharmacoepidemiol Drug Saf. 2013;22(9):1013-1018.
Thorpe PG, Gilboa SM, Hernandez-Diaz S, Lind J, Cragan JD, Briggs G, Kweder S, Friedman JM, Mitchell AA, Honein MA, and the National Birth Defects Prevention Study.
[Read articleexternal icon]

Medication use during pregnancy, with particular focus on prescription drugs: 1976-2008
Am J Obstet Gynecol. 2011;205(1):51.e1-8.
Mitchell AA, Gilboa SM, Werler MM, Kelley KE, Louik C, Hernández-Díaz S, and the National Birth Defects Prevention Study.
[Read articleexternal icon] [Read key findings]

Use of over-the-counter medications during pregnancy
Am J Obstet Gynecol.  2005; 193(3 Pt 1):771-777.
Werler MM, Mitchell AA, Hernandez-Diaz S, Honein MA.
[Read summaryexternal icon]

Read key research findings and clinical guidelines organized by health condition.

View a database of all articles from CDC’s National Center on Birth Defects and Developmental Disabilities from 1990 to present

Page last reviewed: July 16, 2020