Neurocognitive testing

The cognitive scale and the fine motor and gross motor subtests of the Bayley Scales of Infant Development, 3rd Edition (BSID III) screening test were used to assess the infants’ development at 18 months of age [14]. The language domain was not performed because it was not applicable in the setting of Yunan, China. All children were assessed within a two-week window at approximately 18 months of age, and the assessments were administered either by a psychologist familiar with the test or by trained assistants/students. All assistants/students were graduate students majoring in pediatrics who received a two-month intensive training on the BSID III test in the Department of Children and Adolescents Health Care of Xin Hua Hospital affiliated to Shanghai Jiao Tong University School of Medicine. Before the children were evaluated with the BSID III test, the evaluators had been living and working locally in rural Yunnan for several months. All evaluators were able to communicate with the participants and their parents in Mandarin and simple local dialects. Community sites were adapted and arranged to provide a standardized environment for the testing. When tests were administered, the mothers were present. If the child did not cooperate during the test, the evaluator would try again when the child was in a better mood. Each test administration took approximately 30 min. Double data entry was adopted, and the original paper copies of the data were retained for reverification.