Somatomedin Levels in Pregnancy: Longitudinal Study in Healthy Subjects and Patients with Growth Hormone Deficiency*

Abstract Somatomedin (Sm) levels throughout pregnancy were determined in a longitudinal study of four normal women and three patients with GH deficiency by use of the RIA for Sm-A, a newly developed RIA for insulin-like growth factor 2 (IGF-2), and the placenta RRA for Sm-A. In both normal women and those with GH deficiency, there was a continuous rise of immunoreactive Sm-A throughout pregnancy. During the third trimester the levels were 2-fold elevated above the level in nonpregnant age-matched normal subjects. No change of immunoreactive IGF-2 levels was found in the normal pregnant women, whereas an increase from low to normal levels was found in GH-deficient patients during pregnancy. The placenta RRA-Sm-A did not detect the increase of Sm-A immunoactivity in the normal pregnant women, whereas the levels were normalized in GH-deficient patients. After delivery a rapid fall of Sm levels occurred in patients with GH deficiency. The calculated halflives for immunoreactive Sm-A and IGF-2 were 27 and 52 h...