Understanding Breast Cell Changes During Motherhood and Their Impact on Breastfeeding Difficulties

Recent research focusing on the genetic and cellular transformations of the mammary gland during motherhood offers valuable insights into breastfeeding challenges and postpartum breast health. A comprehensive study conducted on mice has mapped the gene expression patterns throughout the breast's developmental cycle, from pre-pregnancy to involution after breastfeeding. This research has produced the most detailed atlas to date of gene activity in the adult mammary gland, revealing how different cell types—such as fat cells, basal cells, and milk-producing cells—change over time.

The scientists analyzed tissue samples at ten distinct time points, observing significant shifts in cellular composition and gene activity during pregnancy, lactation, and involution. They identified that genes linked to breastfeeding problems, like low milk supply, are active not just in milk-producing cells but also in basal cells responsible for milk ejection, indicating that mechanical issues could play a role in breastfeeding difficulties.

Additionally, the study uncovered that genes associated with postpartum breast cancer are activated immediately after weaning across various cell types, including previously overlooked fat cells. This suggests new targets for early detection and prevention strategies for postpartum breast cancer.

The research also highlights the role of imprinted genes—genes expressed depending on parental inheritance—in regulating milk production and breast tissue remodeling. twenty-five of these genes show activity at specific stages, orchestrating the complex processes involved in motherhood.

Hanin emphasized that understanding these genetic mechanisms provides new avenues to support maternal health by predicting and addressing breastfeeding issues and reducing breast cancer risk. Since breastfeeding influences lifelong health, such as reducing the risk of obesity and diabetes in infants, the findings could lead to better support systems for new mothers.

This work deepens our understanding of mammary gland biology and opens opportunities for innovative interventions to improve breastfeeding success and maternal breast health.