Maternal prenatal selenium levels and child risk of neurodevelopmental disorders: A prospective birth cohort study.

The design cannot show that selenium caused autism or ADHD. Autism and other diagnoses came from electronic medical record ICD codes, not gold-standard assessment. Maternal selenium was measured only once, within three days after delivery, so it may not reflect levels at conception or early pregnancy. Selenium intake from diet and supplements was not measured. The cohort was an urban, low-income, minority population in the US, so the results may not apply to other populations. There is no agreed normal RBC selenium level for pregnant women, so the findings do not give a clear cutoff for practice. Many models and subgroup analyses raise multiple-comparison concerns.

The authors declare no other conflict of interest. The article is marked as supported by NIH and U.S. Public Health Service funding.

Do not conclude that high maternal selenium causes autism or that pregnant women should avoid selenium. The study measured maternal red blood cell selenium after delivery, not diet or supplement intake, and it found an association, not proof. The authors say the findings need confirmation.