Profile of Insulin, Growth Hormone and Insulin-like Growth Factors in Human Cord Blood According to Birth Weight

ABSTRACT

PURPOSE: Insulin-like growth factors (IGFs) are mitogenic peptides that are essential for fetal and maternal tissue growth during pregnancy. They circulate primarily with serum IGF-binding protein (IGFBP) which regulates the availability of IGFs to their specific target tissue. This study was performed to examine the relationships between birth weight and IGFs, insulin and growth hormone in the sera of cord blood. METHODS: Fetal serum samples were obtained by direct puncture of the umbilical cord and were stored at -20degrees C until assay. Serum IGF-I, insulin and growth hormone were measured by radioimmunoassay. IGF-II and IGFBP-1 were measured by immunoradiometric assay. RESULTS: The values of insulin, growth hormone, and IGFBP-1 in the cord blood did not significantly correlate with birth weight or gestational age. The values of IGF-I significantly correlated with gestational age (P<0.05). The correlation of IGF-I and birth weight was statistically significant (P<0.05). IGF-II in the sera of cord blood did not significantly correlate with birth weight. CONCLUSION: Cord blood IGF-I level strongly correlated with birth weight, which suggests that IGF-I may play an important role in fetal growth.