MATERNAL AND FETAL INSULIN-LIKE GROWTH-FACTORS AND THEIR BINDING-PROTEINS IN THE 2ND-TRIMESTER AND 3RD-TRIMESTER OF HUMAN-PREGNANCY

The insulin-like growth factors (IGFs) are mitogenic polypeptides whic h circulate bound to a series of at least six binding proteins (IGFBPs ). An increasing body of evidence supports a major role for the IGF in the control of human fetal growth although normal values in the human fetal circulation have not been established. In order to provide an a ccurate reflection of fetal IGFs and IGFBPs in utero, we have sampled fetal blood direct from the umbilical cord at 18-38 weeks of gestation using the technique of cordocentesis. We have measured IGF-I, IGF-II and IGFBP 1-3 in 91 fetuses in order to establish concentrations for t hese parameters in the second and third trimesters of human pregnancy.