. M.,nopause FERTILITY AND STERILITY Vol. 63, No.3, March 1995 Copyright 1995 American Society for Reproductive Medicine Printed on acid-free paper in U. s. A. Endometrial blood flow response to hormone replacement therapy in women with premature ovarian failure: a transvaginal Doppler study Reuwen Achiron, M.D.* David Levran, M.D. Eyal Sivan, M.D. Shlomo Lipitz, M.D. Jehoshua Dor, M.D. Shlomo Mashiach, M.D. Department of Obstetrics and Gynecology, The Chaim Sheba Medical Center, Tel Hashomer, and Sackler School of Medicine, Tel Aviv University, Ramat Aviv, Israel 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. Fertil Steril 1995;63:550-4 Key Words: Endometrial blood flow, transvaginal Doppler ultrasonography In recent years, the development of assisted reproductive techniques enabled women with ovarian Received March 1, 1994; revised and accepted September 21, 1994. * Reprint requests: Reuwen Achiron, M.D., Department ofobstetrics and Gynecology, The Chaim Sheba Medical Center, Tel Hashomer, 52621, Israel (FAX: 972-3-5302081). failure to conceive with oocyte donation (1). Patients with this type of ovarian failure require hormone replacement therapy (HRT) to produce normal endometrial development and support implantation (2). Endometrial response to HRT has been assessed previously by two-dimensional abdominal ultrasonography and correlated with histology and endocrinology (3), The development of 550 Achiron et al. Endometrial blood flow response in premature ovarian failure Fertility and Sterility
variation. The present prospective study was conducted to determine the response of intrauterine blood flow to standard HRT in women with premature ovarian failure who require oocyte donation. MATERIALS AND METHODS Figure 1 Endometrial blood flow velocity waveforms on transvaginal pulsed Doppler US in a patient with premature ovarian failure in (A) pretreatment stage (phase 0) showing a partially continuous forward-end diastolic flow and in (B) phase I showing low impedance during diastole. transvaginal probes with high frequency (6.5 to 7.5 MHz) transducers permit better resolution of the minute morphological changes that occur in the endometrium. Furthermore, pulsed-wave Doppler techniques that are now mounted on the same transducers have provided a better understanding of the physiological and pathological changes in the deeply located pelvic vessels of the female (4). Doppler ultrasound (US) has been used as a noninvasive assay to assess uterine perfusion in assisted reproduction techniques. However, because of its transabdominal application, the study of the uterine arteries has been limited to the uterine exterior (5). Although the technique has been improved further to allow transvaginal color flow mapping of the uterine blood flow changes (6), surprisingly there is no available literature on intrauterine blood flow Vol. 63, No.3, March 1995 Achiron et al. A total of 30 women were recruited to the study: 18 with premature ovarian failure comprised the study group and 12 volunteers with normal 28-day ovarian cycles served as the controls. In both groups the body mass index was normal and ranged from 18 to 27 kg/m2. Ovarian failure was defined as amenorrhea of ;;:::6 months associated with persistently low plasma E2 and elevated plasma FSH levels. All subjects with ovarian failure were included in the oocyte donation program. Chromosome analysis and blood tests for antiovarian antibodies, thyroid function, and PRL assay were carried out. Hormone replacement therapy in women with premature ovarian failure was prescribed as follows: E2 valerate was administered initially at a dose of 1 mg/ d. The dose was increased by 1 mg daily for the next 5 days and then reduced to 2 mg/ d and maintained at that level for the remainder of the cycle. On the 2nd day ofthe reduced E2 dose, 100 mg/d of P was added for the following 6 days, by way of vaginal suppositories (7). Each woman was investigated by transvaginal color Doppler US (8) on five occasions during the hormone replacement cycle and four times during the spontaneous cycle. Doppler flow measurements were grouped according to the day relative to the start (day 1) of treatment or menstruation: [1] early follicular phase (days 5 to 7); [2] late follicular phase (days 11 to 13); [3] early luteal phase (days 15 to 17); and [4] late luteal phase (days 23 to 25). Patients with ovarian failure had baseline Doppler flow investigation a week before the start of the treatment cycle (phase 0). The endometrial blood flow was explored with the use of a color-flow mapping system (Acuson-128XPI0 or Alloka 680EX and Elscint ESI-2000; Elscint Ltd., Haifa, Israel). Only vessels located within 10 mm of the lateral endometrial border were considered adequate for the study. Resistance indexes were calculated for analysis. All examinations were performed by the same investigator (R.A.), with an intraobserver error of ::;;6% (coefficient of variation). Progesterone and E2 were assayed by solid-phase RIA. Blood samples were obtained through venepuncture the same day (08.00) that the sonographic examination was carried out. Endometrial blood flow response in premature ovarian failure 551
Table 1 Range and Mean Resistance Index Values From Endometrial Arteries During HRT and Controls Phase of treatment HRT* Controls P d I (5 to 7) 0.85 ± 0.12 (0.7 to 1.0) II (11 to 13) 0.57 ± 0.15 (0.37 to 1.0) III (15 to 17) 0.67 ± 0.13 (0.47 to 0.9) IV (23 to 25) 0.66 ± 0.18 (0.41 to 0.9) 0.68 ± 0.11 (0.4 to 1.0) <0.05 0.54 ± 0.15 (0.43 to 0.95) NS 0.71 ± 0.27 (0.35 to 0.95) NS 0.64 ± 0.20 (0.39 to 1.00) NS Values are means ± SD with ranges in parentheses. The results of blood flow characteristics through the ovarian cycle in the study and control groups were compared using the two-sample t-test; a P value of < 0.05 was considered significant. Results are presented as mean, standard deviation, and standard error. RESULTS Optimal flow velocity waveforms were obtained in all 18 women with premature ovarian failure and in the 12 controls. Blood-flow waveforms were found consistently in the endometrial vessels of all the patients in both groups. All patients with premature ovarian failure showed a partially continuous forward-end diastolic flow in the pretreatment stage (phase 0), whereas in phase I all showed continuous flow (Fig. 1). After 2 days of estrogen therapy (phase I), arterial waveform analysis demonstrated high impedance to diastolic flow as reflected by the resistance index (0.85 ± 0.5; mean ± SD). Table 1 depicts the range and mean resistance index values at defined times during the treatment cycle in the study and control patients. Significant statistical difference is seen only at phase I: mean resistance index 0.85 versus 0.68 (P < 0.001). The mean and SE for resistance index values in each phase of both groups are shown in Figure 2. Women with ovarian failure in the early follicular phase had a significantly higher resistance index (0.85 ± 0.1; mean ± SE) than that of the late follicular phase (0.57 ± 0.1; mean ± SD; P < 0.001), and the resistance index in the early luteal phase (0.67 ± 0.1; mean ± SD) was significantly higher than that of the late follicular phase (P < 0.001). There was no difference in the resistance index (mean ± SD) between early (0.67 ± 0.1) and late luteal phases (0.66 ± 0.1). An identical pattern was observed in the control group. In both groups the lowest resistance index value was obtained at phase II at the maximal plasma E2 concentrations and, as the E2 declined and P level increased, higher impedance to diastolic flow was recorded, reflected by an increased resistance index. The mean and range of plasma values ofe2 and P are shown in Table 2. Patients with premature ovarian failure had a significantly lower E2 level in phase I of the cycle than the control population (mean 55 ± 78 versus 172 ± 142 pg/ml; conversion factor to SI unit, 3.671; P < 0.02), whereas no differences in plasma values of both E2 and P were recorded in phases II to IV. 0.9 0.8 ~ 1 iii! 0.7, I 0.6 O.S 0 2 3!'base ofi"reaanenl ~ Mea RI Coottol 4 Mea RI 0variaD lliiiure piiiie 1 (day S 7) piiiie 2 (day 11-13) piiiie 3 (day 17 21 piiiie 4 (day 23 25) Figure 2 The mean ± SE for resistance index values in each phase of both groups. DISCUSSION We analyzed endometrial artery response to HRT in women with premature ovarian failure. Apart from the early follicular phase where a significant statistical difference in endometrial blood flow waveforms was found, there was no statistical difference between these women and the controls, who had spontaneous ovarian cycles. As estrogen and P had similar plasma levels in both groups, it is likely that the similarity in endometrial flow response is due to the production of a similar hormonal milieu. It is well known that exogenous estrogen and P ad- 552 Achiron et ai. Endometrial blood flow response in premature ovarian failure Fertility and Sterility
Table 2 Estradiol and P Plasma Levels on the Day of Measuring Endometrial Blood Flow* HRT Controls Phase Pt Pt pg/ml ng/ml pg/ml ng/ml I (5 to 7 d) II (11 to 13 d) III (15 to 17 d) IV (23 to 25 d) 55 ± 78 (10 to 25) 663 ± 192 (400 to 900) 302 ± 219 (100 to 961) 246 ± 105 (130 to 443) 0.3 ± 0.17 (0.1 to 0.6) 0.1 ± 0.15 (0.2 to 0.3) 10 ± 6.3 (2 to 24) 12.9 ± 6.3 (6 to 17) 172 ± 142 (15 to 465) 654 ± 152 (69 to 901) 395 ± 148 (275 to 685) 265 ± 93 (126 to 427) 0.4 ± 0.14 (0.2 to 0.6) 0.3 ± 0.21 (0.1 to 0.7) 7.6 ± 6.4 (0.2 to 16) 15.6 ± 3.3 (12 to 15) * Values are means ± SD with ranges in parentheses. t Conversion factor to SI unit, 3.671. ministration enable histologic and morphological reproduction of the endometrium of a normal cycle (2). Because previous studies have shown the effect of estrogen and P on endometrial morphology (3, 9), and on the flow in the main uterine artery branches (10, 11), we chose to investigate the functional role of these hormones on the endometrial vessels. We have shown that endometrial blood flow increases during the proliferative stage because of reduced downstream impedance manifested by increased diastolic flow. The minimal impedance to flow (the lowest resistance index) was achieved when plasma estrogens reached their maximal concentration. From that point, increased diastolic impedance resulted in decreased flow to the endometrium manifested by increased resistance index during the secretory phase. These changes in the endometrial flow seemed to follow estrogen and P plasma concentrations. Goswamy and Steptoe (12) demonstrated that a normal uterus responds to rising estrogen levels by increasing perfusion, falling estrogen levels by decreasing blood flow, and rising P levels plus estrogen levels in the luteal phase by increasing uterine perfusion. A similar observation was reported by Fleischer (4), who studied five patients in the proliferative midcycle and secretory phases. A trend toward decreased pulsatility indexes was demonstrated (4). Scholtes et al. (6) and Steer et al. (13) compared the pattern of the uterine arteries flow with follicular activity. Although the authors showed a similar pattern of changes in these vessels, the pulsatility index in their studies only marginally followed the observed impedance changes during the menstrual cycle. This may be attributed to the fact that both studies investigated main uterine arteries situated outside the uterus. In our study we found that the changes in endometrial flow were more significant during artificial and spontaneous cycles, probably because for the first time we explored small intrat Conversion factor to SI unit, 3.180. P < 0.002. uterine vessels located at the endometrial region. The impedance to endometrial blood flow was consistently high in women with premature ovarian failure, thus reflecting their persistent hypoestrogenic state. Exogenous administration of estrogen produced decreased endometrial impedance to flow similar to that of normal menstrual cycles. From a clinical point of view, previous preliminary works suggested that decreased uterine perfusion was associated with decreased fertility in IVF cycles (5, 14). Therefore, from our findings, it may be speculated that a woman with premature ovarian failure who achieves adequate endometrial flow response will benefit from an oocyte donation program. However, detailed studies are required to verify this. We have demonstrated that, in women suffering from premature menopause, it is feasible to simulate the same characteristics of endometrial blood flow waveforms of the fertile menstrual cycle with HRT. The endometrial blood flows that were produced may apply to the success of oocyte donation. REFERENCES 1. Sauer MV, Paulsion RJ. Oocyte donation to women with ovarian failure. Contemp Ob Gyn 1989;34:125-35. 2. Navot D, Laufer N, Kopolovic J, Rabinowitz R, Birkenfeld A, Lewin A, et al. Artificially and induced endometrial cycles and establishment of pregnancies in the absence of ovaries. N Engl J Med 1986;314:806-11. 3. Dockery TCL, Ramsewak SS, Klentzeris L, Lenton EA, Cooke ID. The variation of endometrial response to standard hormone replacement therapy in women with premature ovarian failure. An ultrasonographic and histological study. Br J Obstet Gynaecol 1991;98:656-61. 4. Fleischer AC. Ultrasound imaging -2000: assessment of utero-ovarian blood flow with transvaginal color Doppler sonography; potential clinical applications in infertility. Fertil Steril 1991;55:684-91. 5. Goswamy RK, Williams G, Steptoe PC. Decreased uterine perfusion-a cause of infertility. Hum Reprod 1988;3:955-9. Vol. 63, No.3, March 1995 Achiron et al. Endometrial blood flow response in premature ovarian failure 553
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