Intermediate trophoblast is a distinct subtype of trophoblastic tissue that arises from the cytotrophoblast. Intermediate trophoblast is a distinct subtype of trophoblastic tissue that arises from the cytotrophoblast. It is sub-categorized by location: The function of the implantation site intermediate trophoblast is to anchor the placenta to the maternal tissue. Intermediate trophoblasts are thought to be the cell of origin for: