Human endometrial stromal cells inhibit the pro-angiogenic stimulus of hCG in vitro.

During embryo implantation, endometrial angiogenesis is regulated by signals originating from the endometrium itself and the developing embryo. It has been suggested that hCG may play a pro-angiogenic role; therefore, we sought to understand its regulatory role in blood vessel formation in human endometrium using in vivo and in vitro models. In the in vivo model, we screened 16 angiogenesis-related transcripts in the endometrium upon intrauterine administration of hCG.