More than half of women who breastfeed in Catalonia have been exposed to at least one medication during the first year after childbirth. This is the conclusion of a population-based study led by researchers from the Jordi Gol Institute for Primary Care Research (IDIAPJGol), published in the International Breastfeeding Journal, which analysed medication use during breastfeeding in more than 176,000 mother–child pairs between 2010 and 2022.

The study was based on data from the Information System for Research in Primary Care (SIDIAP), in which data from mothers and their infants were linked. This enabled the research team to jointly analyse infant breastfeeding records and maternal drug prescriptions and dispensations. This is the first study of its kind to be conducted in Catalonia.

The study shows that medication use during breastfeeding is like that during pregnancy. Its use is common, especially in the first months after childbirth. The most frequently used medications were iron (25%) and folic acid (15.5%) — supplements that may be indicated during pregnancy or the postpartum period — followed by analgesics (17.7%), mainly paracetamol. Beta-lactam antibiotics, such as amoxicillin, and non-steroidal anti-inflammatory drugs, particularly ibuprofen, were also commonly used.

Higher consumption in the first two months

The results show that medication use is highest during the first two months after childbirth, although it should be noted that most of these products are supplements indicated during pregnancy and the postpartum period, as well as medications used to treat common postpartum conditions such as anaemia, pain or infections. From the second month onwards, consumption decreases, “probably — according to the article — due to awareness of the potential harm that exposure to medications during breastfeeding may cause to infants,” but then increases slightly between six and twelve months.

Maria Giner-Soriano, an IDIAPJGol researcher and first author of the study, points out that this latter increase could be due to the fact that “from the sixth month onwards, many mothers stop breastfeeding and other foods are introduced into infants’ diets, which means they may take medications that, as a precaution, they avoided while breastfeeding.”

For the first time on a large scale in Catalonia, this study has described which medications are used during breastfeeding and at what points during the infant’s first year of life. This provides a solid basis for improving clinical decision-making and guiding future research lines on the safety of medications during breastfeeding.

Article reference

Giner-Soriano M, Ricart GA, Cartanyà-Hueso À, Gomez-Lumbreras A, Vázquez ML, Morros R, Vedia C. Drug exposure during breastfeeding: a descriptive population-based cohort study with SIDIAP database. Int Breastfeed J. 2025 Dec 24. doi: 10.1186/s13006-025-00797-3. Epub ahead of print. PMID: 41444905.