Gestational Diabetes Mellitus, Breastfeeding, and Progression to Type 2 Diabetes: Why Is It So Hard to Achieve the Protective Benefits of Breastfeeding? A Narrative Review

Abstract

Women diagnosed with gestational diabetes mellitus (GDM) face a significantly heightened risk of developing type 2 diabetes mellitus (T2DM) later in life. Breastfeeding (BF) has been identified as a potential strategy to delay or prevent T2DM; however, women with GDM often encounter barriers in initiating and maintaining adequate BF practices compared to those with uncomplicated pregnancies. This paradox prompts an exploration into the causes of these BF challenges and considers the possibility of reverse causation: Does prolonged and intensive BF mitigate the risk of subsequent glucose dysregulation and T2DM? Alternatively, do women with compromised insulin secretion and sensitivity, who are predisposed to T2DM, struggle to sustain intensive BF practices? This narrative review aims to explore the interplay between GDM, BF, and T2DM development by examining the different factors that present BF challenges among women with GDM. Understanding these dynamics is crucial for establishing realistic BF expectations and developing effective clinical and public health strategies to support BF in this high-risk population.

Keywords: breastfeeding; gestational diabetes mellitus; obesity; type 2 diabetes mellitus.

Figure 1

Direct, underlying and indirect factors for breastfeeding disruption among women with GDM. GDM (framed in purple) serves as the precursor to several direct factors (framed in green) contributing to BF difficulties, including altered proliferative and secretory phases of mammary gland development during pregnancy, delayed secretory activation, and low milk supply. Additionally, GDM increases the risk of indirect factors (framed in blue) such as macrosomia and hypoglycemia, which impact BF indirectly. Underlying factors, such as prepregnancy obesity (framed in pinkish-tan), may induce inadequate mammogenesis—a direct factor in BF difficulties (framed in green)—and may also increase the risk of GDM (framed in purple), and prepregnancy obesity is often associated with larger breast size (framed in pinkish-tan). Large breast size can complicate BF technique (framed in blue), potentially triggering delayed secretory activation and a low milk supply (framed in green). In addition to GDM, prepregnancy obesity also precedes indirect factors (framed in blue) contributing to BF difficulties, thereby causing predisposition to direct disruptive factors (framed in green), mediating other indirect factors, or even encouraging patients not to breastfeed and to introduce formula instead (framed in red).