Prospective Associations of In Utero Exposure to Multiple Insecticides with Cord Blood Mitochondria DNA Copy Number and Longitudinal Offspring Telomere Length Shortening

Abstract

Widespread insecticide exposure can cause adverse health outcomes in offspring due to maternal exposure via elevating oxidative stress levels, which may be evidenced through variations in telomere length (TL) and mitochondrial DNA copy number (mtDNAcn). However, the potential risks of in-utero exposure to multiple classes of insecticides at environmentally relevant doses on offspring's TL and mtDNAcn in early life are still poorly understood. This study aimed to elucidate associations between in-utero exposure to organophosphates, pyrethroids, neonicotinoids and cord blood mtDNAcn and offspring TL shortening. Maternal urinary metabolites of these insecticides were repeatedly measured in three trimesters. Relative mtDNAcn (n = 520) in cord blood and relative TL (n = 299) in cord blood & blood samples of three years old toddlers were also measured. The results showed that the first-, second-, and third-trimester insecticide mixtures were all significantly associated with reduced cord blood mtDNAcn, and the association was primarily driven by desmethyl-clothianidin (DM-CLO). Additionally, the second-trimester insecticide mixture was significantly associated with TL attrition, with DM-CLO being the primary contributor. Our findings showed that in-utero insecticide mixture exposure was related to decreased cord blood mtDNAcn and accelerated longitudinal offspring TL attrition, with DM-CLO being the major contributor.