Correlation of endometrial histology, morphometry, and ultrasound appearance after different stimulation protocols for in vitro fertilization.

The role of endometrial factors in controlling embryo implantation is poorly understood. In the present study, histopathology and morphometry were used to investigate differences in endometrial appearance seen by ultrasound (US) in 107 in vitro fertilization patients receiving different superovulation regimens. Seventy-seven patients received clomiphene citrate (CC)/human menopausal gonadotropin (hMG) and 30 buserelin acetate down regulation/hMG. All patients received an endometrial US at the time of embryo transfer (ET). Endometrial biopsies were taken from 17 women (12 CC/hMG, 5 buserelin acetate/hMG) with fertilization failure at the time when ET would normally have occurred. The morphometry results showed that endometrial glandular volume 2 days after oocyte retrieval was significantly reduced after CC/hMG compared with buserelin acetate/hMG, despite the fact that histopathological dating was similar for both groups. In addition, significant differences in endometrial thickness and echogenicity between CC/hMG and buserelin acetate/hMG were evident by US.