Implantation window
Abbildung 1: Plate 1 depicts gradual apposition of blastocyst to endometrium during the onset of the implantation
window, delineated here by putative biomarkers
for endometrial receptivity: integrins (red), pinopodes (violet) and LIF (orange). Trophectodermal integrins (green) on the apical membrane surface of the blastocyst are necessary
for adhesion (Plate 2). Adhesion induces reaction in
trophoblast cells to differentiate into inner
cytotrophoblast (dark pink) and outer syncytiotrophoblast (light pink) layers. Syncytiotrophoblasts are large, polymorph,
possess several nuclei and initially invade the decidua (Plate 3). Trophoblasts now produce
pregnancy-conserving β-hCG (not depicted in this scheme), which stimulates the corpus luteum
to produce progesterone. In plate 4, implantation is complete. The implantation window is now closed.
Keywords:
Implantation,
Implantation,
Reproduktionsmedizin,
Schema,
scheme