Associating prenatal antibiotics exposure with attention deficit hyperactivity disorder symptoms in preschool children: The role of maternal vitamin D

Background: The associations between prenatal antibiotics exposure and attention-deficit/hyperactivity disorder (ADHD) in preschoolers, and the role of maternal vitamin D in these associations, remain to be explored. Objectives: To evaluate the relationships between multiple maternal urinary antibiotics levels and preschoolers' ADHD symptoms, and to identify the potential modifying effects of maternal vitamin D. Methods: Based on a prospective birth cohort, the present study included 2033 mother-child pairs. Maternal urine and serum samples were collected during all three trimesters to measure the urinary concentrations of 43 antibiotics (including two metabolites) and the serum vitamin D levels. The ADHD symptoms of preschoolers were assessed using the Diagnostic and Statistical Manual-oriented ADHD problems scale in the Achenbach Child Behavior Checklist. Multiple informant models in the form of logistic regression were conducted to investigate the associations between prenatal antibiotics exposure and preschooler ADHD symptoms, and these associations were stratified by child sex and maternal vitamin D status. Results: Compared with the lowest tertile concentrations, maternal exposure to the middle tertile concentrations of doxycycline and human antibiotics/preferred as human antibiotics (HAs/PHAs), and the highest tertile concentrations of doxycycline during the first trimester were associated with an increased risk of ADHD symptoms in children. An increased risk of ADHD symptoms was observed in girls exposed to the highest tertile levels of sulfamethazine during the second trimester. Furthermore, pregnant women with vitamin D deficiency have a greater risk of ADHD symptoms in their offspring after exposure to doxycycline in the first trimester. Conclusions: Maternal exposure to doxycycline and HAs/PHAs during the first trimester increases the risk of ADHD symptoms in preschoolers. Mid-pregnancy sulfamethazine exposure increases the risk of ADHD symptoms in girls. Maternal vitamin D deficiency during pregnancy may exacerbate the adverse effects of doxycycline exposure on ADHD symptoms.