Table 2: Mean scores on neurodevelopmental scales at 6, 12, and 24 months of age.

6 Months12 Months24 Months
NMean (SD)NMean (SD)NMean (SD)

Bayley
 Mental development index27195.0 (7.9)258101.3 (9.1)24086.4 (11.7)
 Psychomotor development index27196.2 (11.1)257107.0 (12.8)24098.2 (10.4)

Preschool language scale
 Auditory comprehension270104.6 (12.9)25799.1 (12.9)
 Expressive comprehension27091.1 (13.5)25794.5 (13.8)
 Total score27097.7 (11.3)25796.6 (13.5)