Related Experiment Video
Updated: Jun 17, 2026

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Thimerosal exposure (from tetanus-diphtheria vaccine) during pregnancy and neurodevelopment of breastfed infants at 6
R C Marques1, J G Dórea, J V E Bernardi
1Fundação Universidade Federal de Rondônia. Porto Velho, RO, Brasil.
Aim:
We studied the effect on neurodevelopment of infants who are exposed to thimerosal in tetanus-diphtheria (Td) vaccines during pregnancy.
Methods:
We compared Gesell Developmental Schedules (GDS) of exclusive breastfed infants at 6 months born to mothers who received Td (1 to 3 doses) against those who were born to mothers who did not take such vaccines.
Results:
Compared with the group of infants not exposed to ethylmercury in utero, the infants of exposed mothers showed no significant difference in neurodevelopment delays. Although there was a significant correlation between hair-Hg of mothers and hair-Hg of neonates (Spearman r = 0.353; p = 0.0011), there was no significant correlation between the level of in utero exposure to ethylmercury in Td vaccines and neonate's hair-Hg concentrations (Spearman r = 0.060; p = 0.5922). However, regression analysis showed that GDS at 6 months was significantly associated with total mercury concentration of neonate's hair but was not sensitive to the number of vaccines taken by the mother.
Conclusion:
Early neurodevelopment of exclusively breastfed infants is sensitive to in utero exposure to mercury, but maternal thimerosal exposure in tetanus-diphtheria vaccines per se cannot portend clinical neurodevelopment delays measured by GDS at 6 months.
More Related Videos
Related Concept Videos
Teratogenicity
Development of Immunocompetence
The initial cells that migrate from the fetal thymus settle within the skin and epithelial tissues lining the mouth, digestive tract, and in females, the uterus and vagina. These cells, including skin-based dendritic cells, serve as antigen-presenting cells, playing a key role in T cell activation.
Subsequent T...
Diphtheria
Tetanus
Vaccinations
Development of the Oral Microbiota

