Placenta nutrient transport-related gene expression: the impact of maternal obesity and excessive gestational weight gain.

Objective: Maternal obesity and excess gestational weight gain (GWG) increase the risk of delivering large infants. This study examined the associations between maternal obesity and GWG on the expression of genes involved in fatty acid, amino acid and glucose transport, and the mechanistic target of rapamycin (mTOR) and insulin signaling axes in the placenta.

Methods: Placenta samples were obtained from lean (n = 11) and obese (n = 10) women. Gene expression in the placenta was measured using polymerase chain reaction.

Results: There were no differences in placenta gene expression between the lean and obese women, with the exception of lower expression of mTOR in the women with obesity who delivered male offspring (obese n = 6; lean n = 7). GWG in excess of the upper limit of the body mass index (BMI) specific guidelines was correlated with increased expression of SNAT1 and decreased expression of FABP3, mTOR, IRS1 and IGF1R.

Conclusions: Variations in GWG may alter the expression of genes involved in regulating placental nutrient transport. Future research on placental nutrient transport should account for the sex of the offspring and the percentage of GWG that is gained above the upper limit for the pre-pregnancy BMI.