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 pregnancy. Results of these studies provide better information on the safety and risks of using specific medicines before, during, and after pregnancy. This information supports an individual’s ability to weigh the risks and benefits of medicines 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 people 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 Study (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 people, can report suspected problems directly to the FDA MedWatch Program.

Pregnancy registries

Pregnancy registries are systems for tracking outcomes in pregnant people who take a particular medicine or receive a particular vaccine.  After these people give birth, researchers compare the health of their babies to the health of the babies of people who didn’t 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 website.

Are you a healthcare professional?

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

  • Before prescribing medicines to a person of reproductive age, ask them if they are pregnant or thinking of becoming pregnant. If they are not planning a pregnancy, discuss effective birth control options.
  • Discuss current medicines with your patients, especially people 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.

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

Page last reviewed: September 20, 2022