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But is it safe for my baby?

Mary Hebert and the Obstetric-fetal Pharmacology Research Unit (OPRU) team are exploring how to optimize care for pregnant and lactating women

Mary Hebert and research nurse Maggie Leahy, RN, meet with an expectant mother as part of their study.
Mary Hebert and research nurse Maggie Leahy, RN, meet with an expectant mother as part of their study. Photo: Sarah C.B. Guthrie

How do medications for high blood pressure, depression, and even cancer affect pregnant women and their babies? Mothers and health care providers face a daunting challenge of making health care decisions about these vital medications with limited data.

Mary Hebert knows this dilemma first hand. Years ago when she was pregnant, she was faced with a complicated pregnancy herself and was rather frustrated at the lack of data available on the medications she needed. “I thought by the time I was pregnant the second time, there would be more information. But there wasn’t,” she shared. Given her background as a clinical pharmacist and researcher focusing on medications used in the management of solid organ transplantation, Mary knew she had to do something. Years later, her work on the impact of medications on maternal, fetal and neonatal health continues through two Federal grants. 

“A healthy pregnancy requires consideration of the mother, fetus, and neonate.”—Mary Hebert, Pharmacy Professor and Director, UW Obstetric-Fetal Pharmacology Research Unit (OPRU)

Mary and her OPRU team are looking at how and why one of the most important drug-metabolizing enzymes has much higher activity in pregnant women than in non-pregnant people. Understanding this phenomenon is critical for drug dosing during pregnancy and has implications for 15-20% of the drugs used clinically. For example, one expectant mother had an abnormal heart rhythm and fast heart rate before she was pregnant, which was managed by a medication that was eliminated from the body by this enzyme. Mary and her colleagues found that pregnancy made the activity of this enzyme extremely high.  Consequently, when this woman became pregnant, again her heart rate went dangerously high requiring emergency hospitalization and incremental increases in the dosage to manage her heart condition. It worked and she delivered a healthy baby at term. 

The team approach, including physicians who specialize in maternal and fetal medicine, nurses, social workers, nutritionists, and pharmacists like Mary, through their research and clinical activities makes a profound difference in the quality of patient care for women with complicated pregnancies. “We were the first to study a number of cancer medications during pregnancy to try to understand how dosing is impacted by pregnancy,” Mary said. “Although these pregnancies are considered at high risk for complications, these women delivered healthy infants.”

Mary was also invited to partner on a National Institute of Child Health and Human Development (NICHD) study exploring medications in breast milk and their effect on the nursing infant. Initially, they are looking at ten commonly used medications, including labetalol (high blood pressure), metformin (diabetes), and escitalopram (depression and anxiety).

It’s vital that women pursue answers for their medication questions when pregnant, rather than just discontinuing them. “It might surprise you that conditions such as depression are not just associated with issues related to maternal mental health, they are also associated with complications such as pre-term birth and low birth weight infants.  Sudden discontinuation of chronic medications is often more dangerous than the potential adverse effects of continuing the medications throughout pregnancy.  When considering any medication during pregnancy we need to weigh the risks and benefits taking into consideration the underlying condition.  Ultimately our goal is to have healthy mothers and healthy babies.”

These two grants include a four-year National Institute of General Medicine Sciences (NIGMS) R01 grant (GM124264-02) was funded in 2017 for $2.3M. The second is a $79,000 sub-contract from Duke University for a National Institute of Child Health and Human Development (NICHD) grant funded in 2018; BMS01 contract number HHSN- 275201000003I.


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