Evaluation of a menstrual cup to collect shed endometrium for in vitro studies

OBJECTIVE: To evaluate whether a menstrual cup is a suitable instrument to collect antegradely shed endometrium for in vitro studies. DESIGN: A prospective, descriptive, cell biological and immunohistochemical study. SETTING: Tertiary care university medical center. PATIENT(S): Nine female volunteers with regular cycles. INTERVENTION(S): Menstrual effluent was collected with a menstrual cup. Experience with the menstrual cup was described. Cytospin specimens, frozen sections, and cultures were prepared from the obtained menstrual tissue. MAIN OUTCOME MEASURE(S): The acceptability of the menstrual cup. The presence and viability of endometrial tissue was evaluated using immunohistochemical staining and culture outcome. RESULT(S): All women except one described the menstrual cup as acceptable. Menstrual effluent contained single cells, clumps of cells, and glandlike structures. After 5 days of culture, the endometrial tissue appeared to be viable. Immunohistochemistry showed positive staining for vimentin in most cytospin specimens, in all cryostat specimens, and in 10 of 17 cultures. Cytokeratin 18 stained most cytospin specimens, all cryostat specimens, and 10 of 17 cultures. Positive staining for BW495/36 was observed in most cytospin specimens, all cryostat specimens, and 11 of 17 cultures. CONCLUSION: A menstrual cup in an acceptable instrument to collect antegradely shed menstrual tissue. Menstruum contains viable endometrial tissue that can be used for in vitro studies of endometrium and endometriosis.