Effect of rising hCG levels on the human corpus luteum during early pregnancy

During early pregnancy, the most important task of the corpus luteum (CL) is to produce sufficient progesterone until the luteoplacental shift occurs. Progesterone production is closely related to the extensive vasculature surrounding and supplying the CL. The synthesis of both progesterone and factors controlling the vasculature in the CL is regulated by hCG, which is released initially at rising levels from the placenta. The primary aim of this research was to evaluate changes in the CL vasculature during early pregnancy.