Maternal medications linked to reduced protein and fat in breast milk

Maternal medications linked to reduced protein and fat in breast milk | Image Credit: © Анастасія Стягайло - © Анастасія Стягайло - stock.adobe.com.

Protein and fat levels in milk are reduced by certain maternal infant medications, leading to health risks in breastfed infants, according to a recent study published in JAMA Network Open.¹

Multiple health benefits have been linked to breastfeeding, making it recommended as the only source of nutrients in the first 6 months of life.² The macronutrient levels in human milk usually match the needs of the infant and positively correlate to infant weight and length.¹

Medication is taken by over 70% of breastfeeding women. As phenomena impacting plasma composition may also change milk composition, there is a concern that macronutrient levels in human milk may be influenced by maternal medication.

To evaluate the association between prescription medications and human milk composition, investigators conducted a cross-sectional study. Milk samples were obtained from October 10, 2014, to January 23, 2024, at The University of California, San Diego Human Milk Biorepository (HMB).

Participants included mothers of singleton infants recorded in the HMB database. Those taking long-term medication were placed in a selective serotonin reuptake inhibitors (SSRIs), monoclonal antibodies (MABs), systemic steroids, or other anti-inflammatory drugs (ADs) group.

During sample collection, maternal interviews were performed to obtain data about maternal medical disorders. An online Edinburgh Postnatal Depression Scale was used to screen current mood disorders.

Untreated mothers with inflammatory disorders or mood disorders were defined as disease-matched controls (DMCs). A healthy control group comprised of mothers without exposure to the selected medications or underlying disorders.

Mothers reported prescription medication exposure during telephone interviews occurring at sample collection. Exposure was determined by medication use continuously in the 14 days before sample collection or continued treatment in the case of MABs taken every 4 to 8 weeks.

Carbohydrates, fat, protein, and total energy levels were reported as primary outcomes. Covariates included maternal race and ethnicity, infant and maternal age at sample collection, maternal body mass index (BMI), parity, infant sex, exclusive breastfeeding, times fed per day, collection time of milk sample, maternal cannabis use, and maternal occupation.

There were 384 milk samples included in the analysis, 63 of which were exposed to SSRIs, 63 to MABs, 33 to systemic steroids, and 20 to other anti-inflammatory drugs. Healthy unmedicated mothers provided 64 samples and DMCs provided 141.

Of mothers, 75.8% were non-Hispanic White, 12.5% non-Hispanic Black, 12.5% Hispanic, 7% Asian, and 2.9% other. At sampling, mothers were aged a mean 33.5 years and infants a mean 6.6 months.

A significantly increased BMI was reported among mothers taking SSRIs, at 29.9 vs 25.6 for those taking MABs, 26.3 for those taking steroids, 25.4 for those taking other ADs, 26.1 for DMC mothers, and 25.6 for healthy mothers. Reduced cannabis use was reported in mothers taking anti-inflammatory drugs.

SSRIs were associated with a reduced rate of mood disorders, at 92.1% vs 100% in DMCs. Similarly, all AD exposed groups reported reduced rates of inflammatory disorders.

Exposed groups had a 15% to 21% reduction in crude mean protein content vs healthy mothers. However, this difference only remained significant for SSRIs and steroids after adjustments.

For mean fat and total energy, reductions of 10% to 22% were reported from treatment with other ADs vs samples from DMCs and healthy patients. After adjustment, this difference only remained significant for fat and only when compared with DMC.

These results indicated lower levels of macronutrients in human milk following the use of specific medications. Investigators noted “these results should not affect the breastfeeding recommendations for mothers treated with antidepressants and anti-inflammatory medications.”

Reference

1. Whaites Heinonen E, Bertrand K, Chambers C. Macronutrients in human milk exposed to antidepressant and anti-inflammatory medications. JAMA Netw Open. 2025;8(1):e2453332. doi:10.1001/jamanetworkopen.2024.53332
2. Meek JY, Noble L. Policy statement: breastfeeding and the use of human milk.Pediatrics. 2022;150(1):e2022057988. doi:10.1542/peds.2022-057988