Children born to mothers with mild-to-moderate iodine deficiency at the end of the second trimester do not have an increased likelihood of having a clinical diagnosis of autism spectrum disorder (ASD) compared with those born to mothers with higher iodine status. The findings were published in BMC Pediatrics.
Researchers measured the urinary iodine concentrations (UIC) and iodine/creatinine ratios (I:Cr) in 6639 mothers from the Born in Bradford cohort at 26-28 weeks gestation. ASD diagnoses were determined from children’s primary care records.
The median UIC was 76 (interquartile range [IQR], 45-120) µg/L with 29 per cent samples below 50 µg/L, indicating a deficient population. Median I:Cr was 83 (IQR, 59-121) µg/g. 1.3 per cent of children had a recorded diagnosis of ASD by the census date. After adjusting for established confounders, no association was observed between I:Cr and the risk of ASD diagnosis in children aged 8-12 years (Poverall=.3).
"As such, this study does not rule out the potential for some impact of low maternal iodide intake on ASD or other outcomes in other populations or in future studies with 24-h urines collected through pregnancy, in particular in trimester 1, which would improve precision and target potentially earlier critical windows of exposure," the authors said.
