International adoption, "early" puberty, and underrecorded age.

Internationally adopted children appear to reach puberty at a relatively young age and to have a high risk of early puberty including very early or precocious puberty (PP), that is, pubertal development at,8 years of age for girls and at ,9 years of age for boys. However, there can be uncertainty over the chronological age of adopted children, raising the possibility that the seemingly elevated risk of early puberty is due to some children having a significantly underrecorded age, perhaps of up to 2 years or more. If a child’s birth date is unregistered and relatives are uncertain, or if the child is abandoned, an age will need to be determined to complete adoption formalities. There is no certain method of determining a child’s age, which makes errors in either direction possible. However, it may be suspected that underestimates are more likely than overestimates, either to facilitate placement with adoptive parents, who tend to favor younger children, or because neglected and malnourished children will be less advanced and smaller than the typical child of their age. Researchers into early puberty freely admit that there is an element of uncertainty over birth dates; 1 study reported that a child who entered the recipient state apparently aged 5 years and who later developed early puberty may have been 2 or 3 years older than his recorded age; another classified 25.4% of internationally adopted girls as having an uncertain date of birth. Nonetheless, most researchers have tended to discount underrecorded age as a systemic explanation of the elevated risk of early puberty in favor of theories that assume that, in most cases at least, they are dealing with a genuine diagnosis. However, I would argue that some of the puzzling findings uncovered by the research, on age at adoption, catch-up rates, final height, and height after treatment to delay puberty, can be explained by underrecorded age. Other findings have rendered other theories problematic so that, overall, underrecorded age provides a better explanation of the research evidence than do the alternatives. It has been found that the older the recorded age at adoption the higher the risk of early puberty. Conversely, very young children at adoption are at little or no increased risk of early puberty. Children adopted into Denmark from Korea were found to have no increased risk of PP. Ninety-nine percent of these children were ,2 years or ,1 year of age on arrival in Denmark (both figures are given). AUTHOR: Peter Hayes, PhD