Objective: To study the predictive value of ovarian stromal blood flow (OSBF) measured by Doppler after pituitary suppression in ovarian response to controlled ovarian hyperstimulation (COH) and IVF outcome. Design: Prospective, observational study, that included 105 IVF cycles from March 1 to December 31, 2000. Materials/Methods: Patients received a long protocol for pituitary suppression, had a normal FSH level (<10) and had no ovarian cysts. Their mean age was 30.4 ± 0.6. A vaginal ultrasound was performed on day 1,2 or 3 of menses, to ascertain ovarian quiescence and OSBF indices were studied in both ovaries. Blood flow velocity waveforms (BFVW) were recorded on paper for subsequent analysis. Both ovaries were measured in their three-dimensional diameters, ovarian volume was calculated by the formula: V = D1 × D2 × D3 × 0.523 and the total count of antral follicles was registered. Then, COH was started as previously described (Simón et al, Fertil Steril 1998;70:234–9), without considering the ultrasound measurements. When ≤4 follicles were found, the cycle was cancelled due to low response (LR). Patients were allocated in two groups, according to whether ovarian stromal BFVW were obtained bilaterally by Doppler ultrasound (Group 1, n = 82) or in Group 2 (n = 23) when no BFVW could be measured in one or both ovaries, because no stromal blood flow could be detected. Results: Both groups were comparable in terms of age, BMI or serum hormonal levels after pituitary suppression (data not shown). Their diagnosis was comparable between groups except for low responder patients who were significantly higher in group 2 (34.8% vs 10.9%). The results from the ultrasound measurements and IVF outcome were as follows (see table). Pregnancy and implantation rates were comparable, but the cancellation rate was 1.2% vs 39.1%, in group 1 and 2 respectively (p ≤ 0.001). Results. †Group 1Group 2Ovarian volume (cc)3.7 ± 0.1†p ≤ 0.005,3.1 ± 0.2†p ≤ 0.005,# antral follicles5.5 ± 0.3‡p ≤ 0.001.3.2 ± 0.4‡p ≤ 0.001.Pulsatility Index (PI)1.01 ± 0.031.06 ± 0.09Resistance Index (RI)0.68 ± 0.030.66 ± 0.05Peak systolic velocity (PSV)12.2 ± 0.311.2 ± 0.8FSH total dose (IU)2374.6 ± 83.9†p ≤ 0.005,2874.4 ± 239†p ≤ 0.005,E2 at hCG administration day2374.6 ± 83.9‡p ≤ 0.001.1459.5 ± 228.7‡p ≤ 0.001.# oocytes obtained at ovarian puncture16.7 ± 0.9†p ≤ 0.005,10.3 ± 1.9†p ≤ 0.005,† p ≤ 0.005,‡ p ≤ 0.001. Open table in a new tab Conclusions: The absence of OSBF by doppler ultrasound in one or both ovaries is a poor prognostic factor for IVF cycle outcome. Although higher doses of FSH are used in this group of patients, a significantly higher rate of cycle cancellation due to LR was found. Thus, it may not be a doppler value itself which has a prognostic factor for IVF outcome, but the presence or absence of ovarian stromal blood flow.