A prospective study of prenatal mercury exposure from maternal dental amalgams and autism severity

Acta Neurobiol Exp (Wars). 2009;69(2):189-97.


Dental amalgams containing 50% mercury (Hg) have been used in dentistry for the last 150 years, and Hg exposure during key developmental periods was associated with autism spectrum disorders (ASDs). This study examined increased Hg exposure from maternal dental amalgams during pregnancy among 100 qualifying participants born between 1990-1999 and diagnosed with DSM-IV autism (severe) or ASD (mild). Logistic regression analysis (age, gender, race, and region of residency adjusted) by quintile of maternal dental amalgams during pregnancy revealed the ratio of autism:ASD (severe:mild) were about 1 (no effect) for < or =5 amalgams and increased for > or =6 amalgams. Subjects with > or =6 amalgams were 3.2-fold significantly more likely to be diagnosed with autism (severe) in comparison to ASD (mild) than subjects with < or =5 amalgams. Dental amalgam policies should consider Hg exposure in women before and during the child-bearing age and the possibility of subsequent fetal exposure and adverse outcomes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Autistic Disorder* / chemically induced
  • Autistic Disorder* / classification
  • Child
  • Dental Amalgam / toxicity*
  • Female
  • Humans
  • Logistic Models
  • Male
  • Maternal Exposure*
  • Maternal-Fetal Exchange* / physiology
  • Mental Status Schedule
  • Pregnancy
  • Prospective Studies
  • Severity of Illness Index


  • Dental Amalgam