Growth of children with Down's syndrome: birth to age 3 years.

A sample of 90 children with Down's syndrome were measured for recumbent length and weight from birth to age 36 months at the Children's Hospital Medical Center in Boston. At birth, means for both length and weight were reduced by about 0.5 SDs from the control group means. By 36 months, mean recumbent length was greater than 2 SDs below that for the control group, while the mean for weight was reduced by about 1.5 SDs from the control group mean. Growth velocity for both length and weight was most deficient within the first two years of life. About 30% of the sample demonstrated excess weight for length relations by 36 months. Children with moderate or severe heart disease were significantly smaller than those without or with mild cardiac problems at all times after birth. Measurements of a subsample of children at 4, 5, and 6 years of age suggested that growth velocity after 3 years of age may be within the range of normal. Assessment of growth of the child with Down's syndrome may be carried out with reference to charts plotting tenth to 90th percentiles based on these data.