Page 79 - PRECONGRESS COURSE 04

Apical epithelial glycocalyx, present in vivo, much reduced in vitro
‐‐ part of a barrier system for embryo selection?
Luminal epithelium
Human endometrial mucin MUC1 is up‐regulated by progesterone and down‐regulated in vitro by the human blastocyst. Meseguer M, et al Biol Reprod. 2001 64:590‐601. PMID
Silent failures
• Unselected (ie variable quality) blastocysts, once hatched, have the capacity to attach to endometrial cells
• Themidsecretoryluminalepithelium,whichhasa thick apical glycocalyx, acts as a barrier to progressive attachment
• Anembryonicsignalisrequiredtoremovethe glycocalyx
• So the ‘silent’ (hCG –ve) pregnancies are selected against at the epithelial stage
PRECONGRESS COURSE 04 I GENEVA, SWITZERLAND – 2 JULY 2017 79