Uterine arterial blood flow and the substances of ovarian renin–angiotensin system in women with polycystic ovaries undergoing in vitro fertilization

ObjectiveTo find whether plasma and follicular prorenin concentrations have any effect on the uterine arterial blood flow in women with polycystic ovarian syndrome (PCOS) compared to those with normal menstrual cycles (NMC).Study designControlled prospective clinical study involved 55 women undergoing in vitro fertilization: 24 with PCOS and 31 with NMC. In both groups transvaginal colour Doppler assessment of uterine arterial blood flow was analysed on day 22 of the cycle, on the day of human chorionic gonadotrophin (HCG) administration and 36 h after HCG. Plasma and follicular (in the dominant follicle containing mature oocyte, and in the pooled follicles) prorenin and active renin, and serum estradiol and androstenedione concentrations were measured at these time-points. The Student's t-test and Pearson correlation were used for the statistical analysis.ResultsThe resistance index (RI) in the NMC group decreased from 0.84 ± 0.05 on the day of HCG to 0.78 ± 0.08 36 h after HCG (P < 0.05); in the PCOS group the RI did not decrease. Follicular prorenin concentrations in the dominant follicle and in the pooled follicles were lower in the PCOS than in the NMC group (20,210 ± 10,831 μU/l, 16,753 ± 8634 μU/l versus 42,637 ± 35,400 μU/l, 33,067 ± 26,200 μU/l; P < 0.05).ConclusionsPlasma prorenin concentrations do not affect vascular impedance to the uterine artery, but follicular prorenin do by newly formed low resistant vessels in the follicles.