UTERINE VASCULARITY DURING STIMULATION AND ITS CORRELATION WITH IMPLANTATION IN IN-VITRO FERTILIZATION

The changes in uterine artery blood flow in women under-going in-vitro fertilization cycles were studied throughout stimulation after gonado trophin- releasing hormone (GnRH) desensitization. The data obtained s howed that the uterine vascularity was related to hormonal changes. Th e GnRH agonist effect was seen only after the third week of administra tion, and the uterine perfusion was significantly (P = 0.002) improved by the oestradiol secretion, Human chorionic gonadotrophins increased the resistance index (RI) significantly (P = 0.0001) for a period of 48 h. Then the progesterone secretion modified the curve with a signif icant improvement in the uterine blood flow (P = 0.03). Comparison of the RI value 2 days before human menopausal gonadotrophin (HMG) commen cement, in patients with and without pregnancy, showed a higher RI in patients who did not conceive but no difference was observed on the da y of embryo transfer. The pregnancy rates were similar whatever the ra nge of the RI observed. The data available so far suggest that haemody namic parameters alone, detected by Doppler sonography, do not provide full information on endometrial receptivity on the day of embryo tran sfer. A resistance index > 0.79 before HMG commencement seems to indic ate poor uterine vascularity and may necessitate an increase in the HM G doses to prevent endometrial immaturity.