The simultaneous measurement of parent neonicotinoids and their metabolites in maternal urine, serum, and cord serum enables a comprehensive assessment of prenatal exposure and placental transfer dynamics. In this study, concentrations of parent neonicotinoids and their metabolites were quantified in these three biological matrices among 218 mother-newborn pairs using ultrahigh-performance liquid chromatography tandem mass spectrometry. We assessed the associations of matrix-specific concentrations of parent neonicotinoids and their metabolites with newborn anthropometric measures. We further investigated the interactions between these matrix-specific concentrations and cord serum vitamin levels in relation to neonatal anthropometric measures. Parent neonicotinoids, including clothianidin, thiamethoxam, and imidacloprid, as well as the metabolite N-desmethyl-acetamiprid were frequently detected in all three matrices. Concentrations of parent neonicotinoids and their metabolites were significantly higher in maternal urine than in maternal or cord serum. Cord serum N-desmethyl-acetamiprid was significantly positively associated with head circumference, and a J-shaped joint association was observed between parent neonicotinoids and their metabolites in cord serum and head circumference. Moreover, interaction analysis showed the association between N-desmethyl-acetamiprid and neonatal head circumference varied by vitamins with a negative interaction observed for vitamin A and positive interactions for vitamin E and 25-hydroxyvitamin D2.
Jia et al. (2026) studied this question.