Table 1.

In vitro models to study human endometrium-embryo interaction.

Model format/cell types	Embryo/spheroid	Measures of interaction				References
		Embryo/spheroid	Stromal cells	Epithelial cells	Trophoblast
Monolayer
Primary human endometrial stromal cells	Hatched human blastocysts, high- and low-quality human embryos, human embryo-conditioned media, mouse blastocysts, human trophoblast spheroids, embryonic stem cell-derived trophoblast spheroids	Attachment (apposition and anchoring), trophoblast outgrowth and invasion, hCG secretion	Cell migration, secretion of implantation-associated cytokines, gene expression profiles, calcium signalling, ‘biosensing’ embryo quality			Carver et al. (2003), Grewal et al. (2008, 2010), Teklenburg et al. (2010), Weimar et al. (2012), Brosens et al. (2014), Lee et al. (2015), Berkhout et al. (2018)
Human endometrial stromal cell lines (T-HESC; hTERT-immortalised endometrial stromal cells)	Human trophoblast spheroids (AC-1M88, Sw.71)	*Attachment, expansion, outgrowth and invasion, CEACAM1 expression	Mmigration			Holmberg et al. (2012), Gellersen et al. (2013)
Primary human endometrial epithelial cells	Cleavage stage human embryos and blastocysts, human embryo-conditioned media, mouse blastocysts, human trophoblast spheroids (trophoblast stem cell-, embryonic stem cell-and/or choriocarcinoma -derived)	Blastocyst rate and quality, blastocyst adhesion, spheroid attachment and outgrowth		Gene expression and secretion of implantation-associated chemokines, chemokine receptor expression and localisation, gene expression profiles, morphological assessment		Lindenberg et al. (1985), Simón et al. (1997, 1999), Meseguer et al. (2001), Caballero-Campo et al. (2002), Dominguez et al. (2003), Lee et al. (2015), Le Saint et al. (2019), Evans et al. (2020).
Human endometrial epithelial cell lines (Ishikawa, RL95-2)	Hatched and unhatched human blastocysts, hatched mouse blastocysts, human trophoblast spheroids (trophoblast stem cell-, embryonic stem cell-and/or choriocarcinoma -derived)	Attachment and outgrowth/invasion		Gene expression profiles		Lee et al. (2015), Huang et al. (2017), Berneau et al. (2019), Evans et al. (2020), Ruane et al. (2020).
Layered culture
Primary human endometrial epithelial and stromal cells	Expanded/hatching human blastocysts, trophoblast spheroids (choriocarcinoma, JAr)	Embryo attachment, trophoblast invasion and syncytium formation, spheroid attachment and outgrowth/invasion				Bentin-Ley et al. (2000), Wang et al. (2012)
Human endometrial epithelial cell lines (RL95-2, HEC-1A, Ishikawa), immortalised and primary human endometrial stromal cells	Trophoblast spheroids (Jar choriocarcinoma)	*Attachment and outgrowth/invasion				Evron et al. (2011), Wang et al. (2012)
Transwell culture
Primary human endometrial stromal cells and immortalised cell lines (St-T1b; T-HESC)	Trophoblast cells (AC-1M88)		Mmotility and invasion		Invasiveness	Gellersen et al. (2010, 2013)
Organoids
Primary human endometrial epithelial cells	Embryo conditioned media			Pinopode development, glycodelin secretion profile.		Luddi et al. (2021)
Assembloid
Primary human endometrial epithelial and stromal cells	Hatched human blastocysts	†Expansion and attachment; EM cells: morphology and motility				Rawlings et al. (2021)

*Spheroid; ^†Embryos.

EM cells, endometrial cells.