Assessment of endometrial differentiation and function.

The failure to produce an endometrium which is receptive and able to support implantation may underlie some cases of infertility and represent a contributory factor preventing higher pregnancy rates in IVF. This is of direct relevance to ovarian hyperstimulation protocols which may affect the pattern of endometrial differentiation and function and to patients possessing intrinsic defects in their endometrial response. It is apparent that markers of endometrial differentiation are required, particularly those defining the ability of the tissue to support implantation. The common method of assessing endometrial differentiation by histological evaluation, which has been substantially improved by techniques of morphometric analysis, depend upon alterations in endometrial structure. However, the production of monoclonal antibodies to proteins and epitope-bearing mucins which exhibit specific patterns of expression during the luteal phase now also enables immunohistological assessment of endometrial differentiation. Whether these proteins mediate essential functions is not known but as they represent end-points of hormone action this would suggest that their measurement may form the basis of tests of endometrial function and supplement morphometric analyses.