RESUMEN
INTRODUCTION: The pregnancy period represents the most intense period of growth and development. Pre-pregnancy weight influences weight gain during pregnancy. Leptin is a hormone mainly derived from white adipose tissue, during pregnancy leptin is also produced by the placenta. It has been suggested that the effects of placental leptin on the mother may contribute to endocrine-mediated alterations in energy balance; a dysregulation in leptin levels or its receptors may lead to poor birth outcomes. Therefore, the main goal of the present study was to analyze the differences in birth outcomes by maternal weight with the expression level of leptin receptor in maternal peripheral blood mononuclear cell (PBMC) and placental tissue. METHODS: Women with full-term gestation and its offspring were enrolled. Total RNA from maternal PBMC and placenta was obtained to perform the analysis of expression of the leptin receptor (LEPR) gene trough real-time PCR technique. Data were analyzed using one-way ANOVA or Mann-Whitney u test when applicable. Pearson correlation coefficient was used to determine the relationship between continuous variables (Stata v.13); p ≤ 0.05 was considered statistically significant. RESULTS: No statistically significant differences were found between LEPR expression level and the BMI studied groups in maternal PBMC and placental tissue. Interaction between gestational weight gain (GWG) and LEPR in maternal PBMC explain in a 32% the variability of the newborn weight. CONCLUSIONS: LEPR expression level in maternal PBMC correlates with newborn measurements independent from sex. GWG can affect fetal development by increasing fetal birth weight.