Early pubertal development in children adopted from abroad.

Aims. - Precocious puberty has been more frequently observed in the populat ion of children adopted from abroad. A study was therefore carried out to a ssess the prevalence of this early onset of puberty. Population and methods. - In this study, 13 cases of precocious puberty hav e been examined in ten adopted girls and three adopted boys, and the clinic al characteristics and other contributing factors have been described. In t his study group, three of the cases were familial. In addition, a questionn aire was also completed by 99 French families with children adopted from ab road, and analyzed to determine the frequency of early pubertal development . The parameters included were age, weight and height at the time of adopti on, date of onset of puberty for the girls age at first menstruation, and c urrent height and weight. Results. - It was determined that the 13 children had a very high growth re covery rate from the time that they arrived in France. For the period from time of adoption to the onset of puberty, mean height increased from -1.3 t o +1.5 standard deviation score (SDS) and the mean weight-for-height factor increased from +1.2 to 1.9 SDS. The weight-height recovery rate following adoption seems to be the direct cause of early pubertal development in cert ain children, notably in those with a particularly rapid growth rate (betwe en 6 years 6 months and 8 years 9 months for the girls, and between 8 and 1 0 years for the boys). In children adopted at an early age, a 'biological m emory' seems to exist regarding the renutrition phenomenon which was instru mental in accelerating the onset of puberty some years after adoption. An a nalysis of the survey on the adoptive families showed that the frequency of precocious puberty was 44.9% in the group of 49 girls compared to only 8.6 % in the group of 35 adopted boys, and that it mainly concerned children fr om Africa (57%), followed by those from South and Central America (57%), As ia (45%), and Eastern Europe (29%). Conclusion. - A higher rate of precocious puberty was found in the adopted girls, with a significantly lower rate in the adopted boys. The etiological factors involved seemed to be mainly nutritional, and influenced by leptin and insulin-like growth factor I (IGF1) levels. The role of the latter and their interaction with other factors, particularly the ethnic aspect, rema ins to be determined via the study of a larger series of adopted children. (C) 2000 Editions scientifiques et medicales Elsevier SAS.