Your Pregnancy Matters

Q&A: Is it safe to take medications while breastfeeding?

Your Pregnancy Matters

Nearly half of the 3 million women who breastfeed annually take one or more medications in the months after delivery, according to a new study.

In April, two of my colleagues – Catherine Spong, M.D., Chief of the Division of Maternal-Fetal Medicine, and John Byrne M.D., a second-year MFM fellow – published a commentary on what we know about taking medications while breastfeeding.

As it turns out, what we don’t know is a bigger story.

Their paper, which was published in the New England Journal of Medicine, notes that half of the more than 3 million women who breastfeed annually take one or more medications in the months after delivery. Medication exposure through breast milk might affect between one to two million infants each year.

What's more, Dr. Spong and Dr. Byrne found that only 2% of products listed in LactMed® (a database of information on chemicals and drugs to which breastfeeding women might be exposed) had sufficient information doctors could use as a guide for drug recommendations to patients who are breastfeeding. In other words, while LactMed is a reliable resource, information is limited.

This finding might surprise patients and doctors. I connected with Dr. Spong and Dr. Byrne to learn more and get their expert thoughts on this topic.

You mention the problem with medications and breastfeeding goes beyond knowing the effects of certain drugs. Could you elaborate?

Dr. Byrne: Having a low milk supply is a major reason women stop breastfeeding or supplement their child's nutrition with formula. Some women who want to increase their milk supply turn to medications or dietary supplements. The concern is that these medications are not regulated by the U.S. Food and Drug Administration (FDA) and there is not substantial data on their safety or impact on breastfeeding.

 It's important to talk through milk supply concerns and find a solution. For example, when writing this piece, my wife was breastfeeding our 8-month-old daughter. There were times when she struggled with her milk supply, and she considered using dietary supplements (such as fenugreek) to attempt to increase it. Some women have found success with it, while others have experienced adverse side effects.

We had many conversations about these potential issues, and she decided to use caution and forgo taking the supplements. Instead, she decided to meet with a lactation consultant, who recommended more frequent pumping sessions and assisted in helping her establish a schedule for pumping at work (she is a pediatric hospitalist with a grueling schedule).

Related reading: 4 factors that can decrease breast milk supply – and how to replenish it

Some patients try medications for maternal conditions related to breastfeeding, such as mastitis (a breast infection). Others take medication for chronic conditions such as diabetes or high blood pressure. However, patients often continue taking medications they were prescribed before or during pregnancy while breastfeeding, and breastfeeding can cause body changes, such as increased metabolism, that can make these therapies less effective. Patients should review all medications with a doctor to be sure they're getting appropriate treatment and that their baby is not affected.  

Breast pumping as an alternative to breastfeeding

Shivani Patel, M.D., explains the advantages of exclusive pumping and why some women prefer it over breastfeeding.

What is UT Southwestern doing to close the knowledge gap regarding medications and breastfeeding?

Dr. Spong: UT Southwestern has been at the forefront of this area. For example:

  • Laura G. Greer, M.D., a doctor who completed her fellowship at UT Southwestern, led a study on oseltamivir (Tamiflu), an antiviral drug routinely used to decrease the amount of time people are sick with the flu. She reviewed the amount excreted in breast milk and infant exposure to the medication and found that the drug is likely safe during breastfeeding.
  • Jamie Morgan, M.D., led a study on amlodipine – a medication commonly given to treat hypertension in pregnancy and after delivery. The goal was to find out whether the drug is safe to use in the time after delivery. The study found that amlodipine does cross the placenta but is not detected in breast milk or infant plasma 24 to 48 hours after delivery, indicating that it is likely safe for women to use after giving birth.
  • Currently, UT Southwestern doctors are developing a study to evaluate medication safely used for rheumatologic and gastrointestinal disorders during pregnancy and lactation.

Could you offer some reliable resources for patients who might want to learn more?

Dr. Byrne: There are several online resources and textbooks that can provide valuable information. One resource from the National Library of Medicine is LactMed, the database mentioned before. LactMed lists information about the transfer of drugs and other chemicals through breast milk, as well as possible adverse effects. Keep in mind that, while reliable, information is limited.

Other resources include and Both offer hotlines and resources for women to get expert advice about medication safety during pregnancy and breastfeeding. Also, the FDA has changed drug labeling to try to facilitate the understanding of what is known and the basis for the information. The FDA has moved from the pregnancy risk categories where drugs were labeled as A, B, C, D, and X that made it tough to assess the risk-benefit ratio of certain medications.

The Pregnancy and Lactation Labeling Rule eliminates the letter categories and provides a risk summary as well as a new section for people with reproductive potential. This plan is being phased in over several years and aims to provide a concise, standardized summary of available evidence.

In your paper, you note that only .3% of the National Institutes of Health's 2017 annual budget was allocated to research on this topic. Why do you think this is the case?

Dr. Spong: The National Institutes of Health (NIH) uses a specific system – Research, Condition, and Disease Categories – to determine how much funding is allocated to support different areas. In 2017, codes were added to capture funding for pregnancy and lactation research. Funding requires that applications are submitted, and it is multifactorial, including the number of applications submitted, the outcome of peer review, and those that meet specific strategic areas outlined by the Institutes.

That said, an analysis in the PRGLAC report stated that 20 of the 27 institutes at NIH support at least one grant related to breastfeeding. However, in fiscal year 2017, of the grants reported in NIH’s breastfeeding category, only 9% were related to medication and/or supplement use by lactating women. Approximately $77 million were allocated for research related to breastfeeding, lactation and breast milk by the NIH in 2018. This is only approximately 18% of the total funding allocated to general pregnancy-related research. 

When it comes to medications and breastfeeding, understand that the available information is limited. Use reliable sources to help in your decision-making. Don't be afraid to call your doctor or lactation consultant before taking an over-the-counter drug or prescription medication – we want you to feel confident making decisions for your health and the health of your baby.

To schedule a medication review or an Ob/Gyn visit, call 214-645-8300 or request an appointment online.