Pre- and postnatal trace element levels in primary teeth of children with and without an autism spectrum diagnosis

BACKGROUND: The global prevalence of autism spectrum diagnosis (ASD) is increasing. Fetal and early-life exposure to trace elements has been associated with increased likelihood of ASD, but evidence regarding timing of exposure remains limited. AIM: This study investigates prenatal and early-life exposure to non-essential and essential elements, individually and as mixtures, in children with and without ASD, stratified by child sex. METHODS: The sample included 170 children from the Norwegian Mother, Father and Child Cohort Study (MoBa), of whom 75 were clinically diagnosed with ASD and 95 were not. Elemental levels were measured in primary tooth dentine using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to investigate case-control differences in levels of pre-and postnatal non-essential and essential elements as well as their mixtures. RESULTS: Significant differences in lead (Pb) levels were observed between ASD case and control groups: The ASD male group had lower Pb levels from 15 to 11 weeks prenatally, while ASD female group had lower levels from birth to 4 weeks postnatally, compared to controls. Males with ASD had higher prenatal magnesium (Mg) and lower postnatal Mg levels, as well as lower prenatal lithium (Li) levels and higher postnatal Li levels compared to controls. Additionally, males with ASD had higher prenatal and lower postnatal essential element mixture levels than controls. DISCUSSION: These findings suggest that there may be differential patterns of exposure to non-essential and essential element levels during specific developmental windows in fetal and early postnatal life in children with and without ASD.