A cell from the outer syncytial layer of the trophoblast of an early mammalian embryo, directly associated with the maternal blood supply. It secretes hCG in order to maintain progesterone secretion and sustain a pregnancy. [ GOC:tfm https://www.worldcat.org/search?q=bn%3A0323052908 ]
Synonyms: syncytiotrophoblastic cell syncytial trophoblast cell