Neurodevelopment was assessed using the Bayley Scales of Infant Development
Second Edition, a standardized assessment of cognitive and motor development, with two scores: the Psychomotor Development Index (PDI) and the Mental Development Index (MDI).
The researchers looked at test results from twins who had taken a version of the Bayley Scales of Infant Development
at about 10 months and again at about 2 years of age.
Lactational exposure to either of the two chemicals was not associated with changes in scores on the Bayley Scales of Infant Development
at 6 and 12 months of age (Gladen et al.
To assess the neurodevelopment of infants with and without DP at an average age of six months, US researchers screened 235 case subjects and 237 demographically similar control participants for cognitive and motor development using the Bayley Scales of Infant Development
Cognitive testing consisted of the Bayley Scales of Infant Development
and the Differential Ability Scales.
Cognitive Assessment: General cognitive skills were assessed by administering the Bayley Scales of Infant Development
(Bayley, 1993) at sessions 1 and 3.
The study on adaptive skills and developmental outcomes was based on three measuring tools: International Adoption Questionnaires given to parents; the Bayley Scales of Infant Development
, which yielded a Mental Developmental Index (MDI) score and a Psychomotor Developmental Index (PDI) score; and the Vineland Adaptive Behavior Scale, which measures personal and social skills used for everyday living.
Data were collected from children and their families in five rural Paraguayan barrios on the Bayley Scales of Infant Development
(2nd edition), the Home Observation for the Measurement of the Environment (HOME), and an author-developed measure of family resources, which included questions on breast-feeding practices, waste disposal levels of parental education, parental occupation and presence in the home, language spoken, possession of farm animals, and number of family members living in the home.
The BSID in Latin American Samples The mental (MDI) and motor (PDI) development scales of the Bayley Scales of Infant Development
(BSID) have been used for several decades to assess child development in Latin America.
Cognitive development and language development were assessed directly using the Bayley Scales of Infant Development
, second edition (BSID-II; Bayley, 1993) at 14, 24, and 36 months.
Infants were tested at each follow-up visit, using the Bayley Scales of Infant Development
Further, infant development was evaluated at 12 months using the Bayley Scales of Infant Development
(Bayley, 1969) and the Early Social Communication Scales (Seibert & Hogan, 1982).