Growth-promoting activity of serum throughout pregnancy and at delivery: evaluation by three different bioassays.

Abstract

Somatomedin evolution has been studied by employing three different bioassays in 181 pregnant women from the 7th week of gestation to delivery and in 18 women during the course of labor. In 105 additional mothers of full-term or pre-term neonates a significant increase of a serum growth-promoting activity (thymidine activity) was observed at delivery, as compared to nonpregnant controls, with a progressive return to normal levels in the post-partum period. Different results were found according to the assay method used, suggesting the multiplicity of growth factors and specific adaptations related to the stages of pregnancy.