Prenatal exposure to pyrethroid insecticides has been identified as a risk factor for low birth weight and neurodevelopmental delay in numerous human cohorts. Cypermethrin, a type II pyrethroid, has broad agricultural and household use, and may therefore represent a significant source of exposure to pregnant women. Despite their widespread exposure and significant health effects, little is currently known about the mechanisms by which pyrethroids alter fetal growth and neurodevelopment. Impaired placental function has been linked to both fetal growth restriction and neurodevelopmental delay.
The dual roles of the placenta as both a barrier to fetal toxicant exposure and as a regulator of embryonic growth and neurodevelopment make it a prime target for environmental toxicants. Effects of cypermethrin on the placenta are predicted due to the critical roles that well-established molecular targets of cypermethrin play in regulating placental nutrient transfer and hormone synthesis. As such, the researchers hypothesize that the impairments in fetal growth and neurodevelopment resulting from maternal exposure to cypermethrin are both consequences of altered placental function. Experiments will be performed to characterize the effects of cypermethrin on placental growth and function, as well as assess mechanisms relevant to altered nutrient transfer and neurodevelopmental programming. In addition, the researchers will investigate the effect of maternal exposure to cypermethrin on embryonic neurodevelopment with a focus on pathological outcomes consistent with placental insufficiency. In order to determine whether these effects on neurodevelopment can be attributed to cypermethrin’s direct effects on embryonic brain or through an indirect placenta-mediated mechanism, researchers will measure concentrations of cypermethrin in maternal, placental, and fetal tissue. These experiments are aimed at identifying novel placenta-mediated mechanisms for cypermethrin toxicity in order to better understand the adverse health effects associated with environmentally relevant pyrethroid exposures. Understanding the mechanisms responsible for these health effects is critical for instituting proper regulatory measures.