Endometrial differentiation in the peri-implantation phase of women with recurrent miscarriage: a morphological and immunohistochemical study.

Objectives: To study endometrial differentiation in the peri-implantation phase of women with recurrent miscarriage and to compare the results with endometrium of normal fertile women.

Design: A prospective study of endometrial specimens precisely timed from the LH surge, using traditional histologic dating (Noyes' criteria), quantitative histologic measurement (morphometric analysis), and immunohistochemical techniques.

Results: Fifteen of 25 (60%) subjects in the recurrent miscarriage group had retarded endometrial development in the peri-implantation period as monitored by morphometry. The recurrent miscarriage group showed reduced levels of four mucin-related secretory epitopes, and greater reductions were associated with morphological retardation. Normal differentiation was observed in all of the 14 subjects in the control group.

Conclusions: Women with idiopathic recurrent pregnancy loss may be divided into two distinct subgroups on the basis of their endometrial response in the peri-implantation period. Precisely timed endometrial biopsy should be incorporated in the investigation of recurrent miscarriage.