Cognitive development
At 1y and 2y, child cognitive development was measured using the Bayley Scales of Infant Development-III (BSID-III) [At 6-7y follow up, child intellectual development was assessed using the Wechsler Intelligence Scale for Children®—Fourth Edition (WISC–IV)  [All measures of cognitive development were directly administered by well-trained researchers in a quiet room at community health centers in the presence of the caregiver. Raw summary scores for each of the subtests were computed as described in the test manuals and then transformed to composite scores (with mean ± SD of 100 ± 15, ranged 40–160). Average scores of the cognitive and language domains obtained from BSID-III were generated as a composite measure of cognitive development at ages 1y and 2y to compare with the FSIQ – a combination of cognition and language domains at 6-7y from the WISC-IV.