Extent of Medication Use in Breastfeeding Women

Background: The types of and extent to which medications are used by breastfeeding women have not been thoroughly investigated in the United States. The relationship between medication use during pregnancy and lactation has also been insufficiently investigated. Methods: A survey was given to a cohort of women who delivered their babies at a single center. The participants were asked to record the medications they had taken during pregnancy and subsequently were contacted each month during lactation to determine what medications they had taken. Results: Breastfeeding women took significantly more medications per month than pregnant women (p < 0.0001). Women who were breastfeeding also took prescription medications more frequently than women who were pregnant (p < 0.0001). The number of medications taken per month showed no trend throughout the course of breastfeeding. The medications most often used by breastfeeding women were multivitamins, nonsteroidal anti-inflammatory drugs, acetaminophen, progestins, antimicrobials, and decongestants. Over a third of the subjects took medications rated possibly or probably unsafe, or had unknown safety. Conclusion: The women in this study took more prescription and nonprescription medications while breastfeeding than they did during pregnancy. Many of the medications taken have unknown safety for the breastfed infant. The results of this study should direct further research toward determining the safety of medications commonly used during lactation and to promote the labeling of these medications.