Heart Rate Variability in Newborns From Diabetic Mothers: Clinical Application and Significance

Gestational diabetes mellitus (GDM) is one of the most common pregnancy complications, arising from inadequate insulin secretion and increased maternal insulin resistance. Globally, GDM affects up to 16%-17% of pregnancies, with higher prevalence in low- and middle-income countries. Poorly controlled maternal hyperglycemia increases the risk of congenital malformations, intrauterine death, macrosomia, and metabolic disturbances, and contributes to long-term vulnerabilities including obesity, type 2 diabetes, and cardiovascular disease in offspring. Beyond its metabolic consequences, GDM is increasingly recognized as a prenatal condition capable of shaping fetal developmental trajectories. Emerging evidence indicates that maternal hyperglycemia influences the maturation of the autonomic nervous system (ANS), with measurable effects on neonatal heart rate variability (HRV), a widely used non-invasive proxy of autonomic function, although not a direct measure of sympathetic and parasympathetic activity. Findings from fetal magnetocardiography and neonatal electrocardiography show that exposure to GDM is associated with altered HRV profiles, such as sympathetic predominance, reduced autonomic flexibility, or atypical vagal modulation, depending on perinatal physiology. These patterns suggest that ANS dysregulation can originate in utero and persist into the early postnatal period. This educational review examines the biological and pathophysiological mechanisms linking maternal hyperglycemia to impaired ANS development in fetuses and newborns. Alongside epidemiological and clinical data on infants born to mothers with GDM, it synthesizes recent evidence positioning HRV as a potential early biomarker of autonomic dysregulation. Ultimately, GDM's influence extends beyond glycemic imbalance, affecting the neurobiological foundations of autonomic function and potentially identifying neonates at risk for later cardiometabolic complications.