Mammary gland development and function in maternal obesity and gestational diabetes

The mammary gland undergoes dynamic structural and functional remodeling during pregnancy to prepare for lactogenesis, driven by cellular signaling, immune interactions, and microenvironmental cues, including those from adipocytes. In maternal obesity, clinical data indicate that these patients often experience poor breastfeeding outcomes. The causes are multifactorial, but one contributing factor is impaired mammary gland development and function. The mechanisms underlying poor lactation outcomes resulting from obesity-induced mammary gland dysfunction remain poorly understood. To date, there are no FDA-approved galactagogues, which are milk production-promoting medications, highlighting a lack of treatments and understanding of functional lactation biology. In this review, we examine current literature on mammary gland development and dysfunction with a particular focus on the effects of maternal obesity during pregnancy and lactation.