Maternal–Neonatal Metabolic Continuity and Early Postnatal HPG Axis Activity in Healthy Term Neonates

BACKGROUND: Leptin integrates metabolic and reproductive signaling later in life; however, whether maternal metabolic cues influence early neonatal hypothalamic-pituitary-gonadal (HPG) axis activity remains unclear. OBJECTIVE: To evaluate associations between maternal metabolic markers and early neonatal reproductive hormone activity. METHODS: Forty healthy term neonates (20 males) were prospectively evaluated. Maternal venous blood samples were collected at delivery, and neonatal blood samples were obtained within the first 24 h after birth. Maternal and neonatal adipokines and reproductive hormones were analyzed using correlation and simplified multivariable regression analyses. False discovery rate (FDR) correction using the Benjamini-Hochberg procedure was applied for multiple testing. RESULTS: Maternal leptin was positively associated with neonatal leptin concentrations (r = 0.52, p = 0.001; adjusted β = 0.47, p = 0.001), supporting maternal-neonatal metabolic continuity. However, maternal leptin was not significantly associated with neonatal LH concentrations (β = 0.00009, p = 0.347). Sex remained the strongest independent predictor of neonatal LH levels (β = 1.21, p = 0.011). Neonatal leptin was positively associated with triceps skinfold thickness (β = 1503.14, p = 0.034). Most exploratory associations did not remain statistically significant after FDR correction. CONCLUSIONS: Maternal metabolic markers were associated with neonatal metabolic parameters but were not strongly associated with early neonatal gonadotropin levels in this cohort. Larger longitudinal studies are required to clarify potential interactions between metabolic and reproductive pathways during later phases of mini-puberty.