label: Syncytiotrophoblast
label_lc: syncytiotrophoblast
description: "The superficial, multinucleated layer of the trophoblast, which forms and expands throughout pregnancy to eventually surround the entire embryo. It forms the epithelial covering of the villous tree, mediates implantation of the conceptus into the uterine wall, and is the main endocrine component of the placenta."