VAGINAL COLOR DOPPLER ASSESSMENT OF UTERINE ARTERY IMPEDANCE CORRELATES WITH IMMUNOHISTOCHEMICAL MARKERS OF ENDOMETRIAL RECEPTIVITY REQUIRED FOR THE IMPLANTATION OF AN EMBRYO

Objective: To investigate the correlation between uterine artery imped ance with immunohistochemical, histologic, and ultrasonographic marker s of uterine receptivity. Design: A prospective study of subfertile wo men undergoing a frozen embryo replacement cycle. Setting: A tertiary infertility clinic. Patients: The study was based on 86 patients who h ad failed to become pregnant during a standard IVF treatment cycle and who had at least two good quality embryos cryopreserved. Intervention s: All patients had pituitary desensitization with the GnRH analogue b userelin acetate, followed by E(2) and P replacement therapy. Vaginal color Doppler images of both uterine arteries were obtained on days 7, 14, and 21 of the first (trial) cycle. On day 21, an endometrial biop sy was taken for dating a 24-kd protein, placental protein 14, and E(2 ) receptor assessment. After a menstrual bleed had been induced, admin istration of estrogen and P was reinstituted and embryos transferred t o the uterus on the 3rd or 4th day of P administration. Main Outcome M easures: The mean pulsatility index of the left and right uterine arte ries, a semiquantitative score of endometrial 24-kd protein, PP14, and E(2) receptor assessment, endometrial histologic dating, and pregnanc y outcome.Results: Nineteen of 76 patients who had a successful ET bec ame pregnant. The pulsatility index on day 14 of both the trial and ET cycles was significantly lower in those who achieved pregnancy as com pared with those who did not conceive: 2.65 (range 1.3 to 3.4) versus 3.85 (1.8 to 6.8) and 2.85 (1.4 to 3.6) versus 4.15 (2.1 to 6.8), resp ectively. There were significant correlations between pulsatility inde x and 24-kd protein, E(2) receptor, and endometrial histology but not with PP14 and endometrial thickness. Conclusions: Uterine artery imped ance has a significant correlation with biochemical markers of uterine receptivity and accurately predicts the probability of pregnancy in f rozen embryo replace ment cycles. It is a useful method for assessing uterine receptivity in assisted conception programs.