Objective: To show whether a macrosomic neonate continues to be large through infancy and early childhood.

Design: Retrospective study

Subjects: 485 macrosomic infants weighing > 4000 g and 471 infants weighing between 3200-3600 g born in a four year period.

Main outcome measures: Body weight(WT),) head circumference (HC) and crown heel length (CHL) assessed routinely monthly the first 12 months and at 18, 24, 36, and 42 months of age.

Methods: The LMS method for estimating age-specific reference centiles curves.

Results: WT. Between 0-10 months there is a sharp increase in weight. The upward trend continues to be present even in later months. The position of the centiles are visibly different for the two groups and there is about 25% difference between the centiles that is 75 centile for large infants in the same position with 50 centile for control infant. HC. There is a rapid increase in HC during the early months (up to 1 year of age), becoming less obvious after 14 months. Large and control infants and children's are in two distinct groups until the age of 42 months. Centiles start with a difference of 20% near birth, going down to about 10% later on. CHL low and high centile seems to have similar trends but in different quantities. But the initial difference of 20% between centiles is clearly visible in lower centiles, declines rapidly after 14 months of age. For higher centiles the difference is noticeable until about the 18 months of age declining after the age 30 months.

CONCLUSION: Centile patterns are similar in all parameters. Macrosomic infants continue to be large until the 42 months of age, with differences slowly declining after about the 18 months of age.