The trophoblast (from Greek trephein: to feed; and blastos: germinator) is the outer layer of cells of the blastocyst. Trophoblasts are present four days after fertilization in humans. [1]

The trophoblast originates from the trophectoderm (see below) and differentiates into multiple specialized trophoblast subpopulations and phenotypes. They either differentiate into polar cells …

trophoblast: The membrane of cells that forms the wall of a blastocyst during early pregnancy, and also provides nutrients to the embryo and later develops into part of the placenta.

During this period the trophoblast layer proliferates and differentiates into two distinct layers (syncitiotrophoblast and cytotrophoblast). Following implantation, trophoblast cells continue to …

The intermediate trophoblast on the villous surface forms trophoblastic columns that anchor the fetal part of placenta to the implantation site. In all other locations, the trophoblast is referred to as extravillous …

The initial layer of trophoblast cells, known as the trophectoderm, is contiguous with the embryonic ectoderm. As pregnancy progresses, trophoblasts undergo rapid proliferation and differentiation, …

The trophoblast plays an important role later in the development of the placenta or afterbirth. The conceptus makes contact with the uterine lining about the fifth or sixth day after conception.…

The trophoblast During implantation the trophoblast differentiates itself into two layers: the syncytiotrophoblast (ST) the cytotrophoblast (CT) The syncytiotrophoblast forms an external layer …

Aug 23, 2023 · Originating from the outer layer of the blastocyst—the early stage embryo—trophoblast cells have the primary functions of facilitating embryo implantation and interfacing with the maternal …

Apr 13, 2026 · Here, we report marked downregulation of IL33 (interleukin 33) in villi from unexplained recurrent pregnancy loss (URPL) patients, concomitant with elevated trophoblast senescence. More …