Received May 09, 2006
Accepted August 21, 2006

Currently, most IVF cycles are performed using GnRH analogues with the long protocol. This practice aims to avoid premature LH surge and unscheduled ovulation, thus reducing the risk of cycle cancellation. The diagnosis of pituitary blockade is performed by measuring the serum levels of E2 and by measuring the endometrial thickness and identification of ovarian cysts by means of ultrasonography. In this study, we evaluated Dopplerflowmetry of the uterine arteries as a diagnostic method for the hypoestrogenic state caused by the pituitary block after the administration of GnRHa in IVF cycles. Seventy patients who underwent Assisted Reproduction treatment were selected. Ten days after the administration of GnRHa, serum levels of E2 and endovaginal ultrasound were performed to measure endometrial thickness, evaluate ovarian morphology and Dopplerfl uxometry of the uterine arteries. Considering E2 values ​​<30 pg/ml as the gold standard, the measurement of endometrial thickness showed a sensitivity of 77.8% and a specificity of 61.7%, whereas with Dopplerfl uxometry, the sensitivity was 72.2% and the specificity of 71%. Combining the two methods, we found a specificity of 83.15%. We conclude that the Dopplerfl uxometric study of the uterine arteries can be an important tool in the diagnosis of the hypoestrogenic state in assisted reproduction cycles after the use of GnRHa.