Endometrial factors in recurrent miscarriage.

Recurrent pregnancy loss may be a consequence of an abnormal embryonic karyotype, or maternal factors affecting the endometrium resulting in defective implantation. In order to study the endometrial factors responsible for recurrent pregnancy loss, endometrial biopsy samples should be precisely timed according to the LH surge, and the investigation should be carried out in a non-conception cycle, prior to the next pregnancy. The various methods of studying the endometrium including morphological studies, morphometry, immunohistrochemistry, measurement of endometrial protein in plasma and uterine flushings, cytokine expression in endometrial cells, leukocyte populations in the endometrium and ultrasonographic and hysteroscopic studies, were reviewed. The clinical relevance of the observed abnormality depends on whether or not the abnormality is persistent in subsequent cycles, and if the observed abnormality is of significant prognostic value. Very little is known about the treatment of endometrial defect associated with recurrent pregnancy loss, but preliminary data suggest that the use of HMG may be of benefit.