Associations of cadmium, bisphenol A and polychlorinated biphenyl co-exposure in utero with placental gene expression and neonatal outcomes

•Birth weight was negatively correlated with placental Cd and cord blood PCB levels.•Positive associations were found between KISS1 expression and Cd, BPA, and PCBs.•Gender effects on the expressions of KISS1 and leptin receptor were observed.•Birth weight was negatively associated with KISS1 expression. In utero co-exposure to endocrine disrupting compounds can perturb fetal development. However, the effect of co-exposure on pivotal regulatory genes has seldom been investigated. We explored the effects of in utero co-exposure to cadmium (Cd), bisphenol A (BPA) and polychlorinated biphenyls (PCBs) on master regulator genes. We recruited 284 healthy pregnant women, of whom 262 provided both cord blood and placenta samples, and 200 had all measurements taken. Placental Cd, cord blood BPA and total PCBs in the exposed group were higher than a reference group. KISS1 expression level in placental tissue was threefold higher in the exposed group than in the reference, and was positively associated with all toxicants. Leptin and leptin receptor expression were also significantly higher, but were only associated with BPA. From our findings, we conclude that lower birth weight is correlated with Cd and PCBs, and may result from the increased KISS1 mRNA expression.