Fetal Metabolic Gene Expression In Cord Blood Is Correlated To Neonatal Adiposity

PURPOSE: Neonatal adiposity is correlated with the development of childhood overweight/obesity. Maternal metabolic health during pregnancy is associated with neonatal adiposity at parturition. However, the relationships between maternal and fetal metabolism are understudied, specifically the expression of target genes known to regulate lipid oxidation (CPT1A, and PGC-1α) and insulin sensitivity (ADIPOR 1 & 2). These may offer important insight on pathways that connect maternal and neonatal health, offering potential for future therapeutic targets. The purpose of this study was to explore the relationship between the expression of target metabolic genes in cord blood and neonatal anthropometrics. METHODS: Pregnant persons with GDM (gestational diabetes mellitus) were excluded. Cord blood samples (N = 25) were collected at delivery. RNA was isolated from cord blood and mRNA expression were quantified for metabolic genes [adiponectin receptor 1 (ADIPOR1), adiponectin receptor 2 (ADIPOR2), carnitine palmitoyltransferase 1A (CPT1A), PPARγ coactivator (PGC-1α)] using RTPCR. Ponderal Index (PI), an indicator of neonatal weight status/growth, was calculated using birthweight and length. Data were analyzed using descriptive statistics and normality was assessed for continuous variables using Shapiro-Wilk tests. Correlation coefficients were used to assess associations between variables. Partial correlations were used to adjust for potential co-founders. RESULTS: All neonates were delivered at term (≥37 weeks) and birthweight ranged from 2760-4150 grams. The average PI was 2.51 ± 0.26 kg/m3 (range 2.05 to 3.18 kg/m3). mRNA expression of all genes were positively correlated to PI (ADIPOR: r = 0.448,p = 0.025; ADIPOR2: r = 0.550,p = 0.004; CPT1A: r = 0.533,p = 0.006; PGC-1α: r = 0.478,p = 0.016) and these relationships remained after controlling for gestational age at delivery, baby sex, and maternal pre-pregnancy BMI (p < 0.05). CONCLUSIONS: It has been established that maternal lipid metabolism is associated with neonatal anthropometrics. Findings from this study suggest that the relationship between maternal metabolism and neonatal anthropometrics may be mediated by the neonate’s metabolic profile, particularly genes associated with lipid oxidation and insulin sensitivity.