part_of part of part of bearer of has characteristic trophoblast cell syncytiotrophoblast cell 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. syncytial trophoblast cell syncytiotrophoblastic cell FMA:83043 syntrophoblast cell plasmidotrophoblast cell syncytial cell multinucleate syncytiotrophoblast