Turner's syndrome patients lack tight junctions between uterine epithelial cells

: Eleven endometrial biopsies, taken from six Turner's syndrome patients receiving hormone replacement therapy prior to treatment by oocyte donation and embryo transfer, were assessed by freeze fracture followed by electron microscopy for epithelial tight junctions. Nine of the eleven biopsies had no discernible tight junctions; the other two biopsies had reduced and disorganized junctional structures. Two patients subsequently became pregnant following embryo transfer. It is concluded that compromised epithelial integrity does not prevent embryo implantation in the human, an observation that is consistent with a barrier role for the epithelium except at times when appropriately conditioned with oestrogen and progesterone to induce receptivity for implantation.