Context: Fetal development is thought to be gender-specific for adiposity and for circulating insulin and IGF-I, but not for adipokinemia, as judged by serum visfatin and adiponectin at term birth. We studied the potential relationship between these gender specificities and fetal growth.

Setting: University Hospital.

Study Population: 96 strictly matched neonates born appropriate-for-gestational-age (AGA; 24 girls, 24 boys) or small-for-gestational-age (SGA; 24 girls, 24 boys).

Main Outcomes: serum insulin, IGF-I, visfatin, total and high-molecular-weight (HMW) adiponectin, osteocalcin at term birth; neonatal body composition by absorptiometry.

Results: Cord insulin and IGF-I levels were higher in girls than in boys (P0.01), both in the AGA and in the SGA subpopulation. In AGA newborns, fat and lean mass were each gender-specific (P<0.0001), while visfatin, total and HMW adiponectin were not. Conversely, in SGA newborns, visfatin and HMW adiponectin were gender-specific (higher levels in girls), while body adiposity was not. In SGA fetuses, the distribution of adiponectin isoforms was in both genders shifted towards HMW (P<0.005 vs AGA). Cord osteocalcin did not differ by either gender or birthweight.

Conclusion: At term birth, the gender specificity of adiposity and of circulating visfatin and HMW adiponectin appeared to depend on prenatal growth, whereas the gender specificity of insulin and IGF-I levels did not. The fetal shift in adiponectin isoforms may contribute to explain why SGA newborns tend to be hypersensitive to insulin.