The 3D vascular status of the follicle after HCG administration is qualitatively rather than quantitatively associated with its reproductive competence

Abstract

The objective of this study was to determine whether the vascular status of a single pre-ovulatory follicle is associated quantitatively and/or qualitatively with its reproductive competence. We studied 61 monofollicular IVF-embryo transfer cycles. Just before single oocyte retrieval, follicle vascularization was detected by transvaginal power-Doppler, 3-dimensionally reconstructed, and analysed quantitatively by coloured/gray voxel ratio [vascularization index (VI)] and qualitatively by blood cell displacement [flow index (FI)] calculation. Cycles were sorted in two sets of two groups: low VI (<or=8%, n = 44) and high VI (>8%, n = 17); low FI (<or=30, n = 22) and high FI (>30, n = 39). Patients' characteristics, fertilization rates, and embryo morphology were comparable in all groups. In contrast, clinical pregnancy rates/oocyte retrieval (4% versus 33%, P < 0.009) and implantation rates (11% versus 50%, P < 0.04) were markedly poorer in the low as compared to the high FI groups, respectively, but remained similar between the low and the high VI groups (22% versus 23% and 38% versus 44%, respectively). A qualitative (FI) rather than quantitative (VI) relationship exists between vascular status and functional quality of the follicle after HCG administration.