Endometrial blood flow response to hormone replacement therapy in women with premature ovarian failure: A transvaginal Doppler study

Objective: To evaluate the endometrial blood flow response to hormone replacement therapy (HRT) in women with premature ovarian failure who plan to enter an oocyte donation program. Design: Transvaginal color Doppler ultrasound examinations were performed in women with ovarian failure before and during a cycle of standard HRT and in those with normal menstrual cycles. Blood flow response was assessed by visualization of arterial wave forms in the endometrial region. The transvaginal color flow mapping system was used. Resistance indexes were calculated for analysis and correlated with plasma E₂ and P concentrations. Patients: Eighteen women with ovarian failure (study group), and 12 volunteers with normal ovarian cycles (control group). Results: Data for resistance indexes were divided into five phases according to the day of hormonal cycle: 0, pretreatment phase; I, early follicular phase (days 5 to 7); II, late follicular phase (days 11 to 13); III, early luteal phase (days 17 to 21); and IV, late luteal phase (days 23 to 25). All women with ovarian failure demonstrated continuous forward end-diastolic flow velocities at phase I, whereas none showed this pattern during the pretreatment period (phase 0). Women with ovarian failure in the early follicular phase had a significantly higher resistance index (0.85 ± 0.1; mean ± SD) than that in the late follicular phase (0.57 ± 0.1), and the resistance index in the early luteal phase (0.67 ± 0.1) was significantly higher than that of the late follicular phase. There was no difference in the resistance index between early and late luteal phases. A similar pattern of lower resistance index around midcycle was observed in the control group. However, a comparison of the resistance indexes between ovarian failure and control patients revealed a significant difference between values in the early follicular phase only (0.85 ± 0.1 versus 0.68 ± 0.1). In the late follicular phase and during the entire luteal phase, the mean resistance index did not differ between the study and control groups. Conclusions: The observed data suggest that standard HRT in women with premature ovarian failure enables restoration of endometrial blood flow to normal. This may imply uterine receptivity for oocyte donation.