Comparison of uterine blood flow characteristics between spontaneous and stimulated cycles before embryo transfer

A mathematical model of vascular and hemodynamics changes in early and late forms of preeclampsia

Preeclampsia-eclampsia syndrome is a leading cause of maternal mortality. The precise etiology of preeclampsia is still not well-defined and different forms exist, including early and late forms or preeclampsia, which may arise via distinctly different mechanisms. Low-dose aspirin administered at the end of the first trimester in women identified as high risk has been shown to reduce the incidence of early, but not late, preeclampsia; however, current risk factors show only fair predictive capability. There is a pressing need to develop accurate descriptions for the different forms of preeclampsia. This paper presents 1D fluid, solid, growth, and remodeling models for pregnancies complicated with early and late forms of preeclampsia. Simulations affirm a broad set of literature results that early forms of preeclampsia are characterized by elevated uterine artery pulsatility index (UA-PI) and total peripheral resistance (TPR) and lower cardiac output (CO), with modestly increased mean arterial blood pressure (MAP) in the first half of pregnancy, with elevation of TPR and MAP beginning at 20 weeks. Conversely, late forms of preeclampsia are characterized by only slightly elevated UA-PI and normal pre-term TPR, and slightly elevated MAP and CO throughout pregnancy, with increased TPR and MAP beginning after 34 weeks. Results suggest that preexisting arterial stiffness may be elevated in women that develop both early forms and late forms of preeclampsia; however, data that verify these results are lacking in the literature. Pulse wave velocity increases in early- and late-preeclampsia, coincident with increases in blood pressure; however, these increases are mainly due to the strain-stiffening response of larger arteries, rather than arterial remodeling-derived changes in material properties. These simulations affirm that early forms of preeclampsia may be associated with abnormal placentation, whereas late forms may be more closely associated with preexisting maternal cardiovascular factors; simulations also highlight several critical gaps in available data.

Cyclic changes in T2* relaxometry of human uterus during the menstrual cycle using BOLD MR imaging

PURPOSE

To evaluate dynamic changes of T2* values within the endometrium, junctional zone and myometrium during the menstrual cycle using blood oxygen level-dependent (BOLD) magnetic resonance imaging.

METHOD

Volunteers underwent MRI scans on menstrual phase, ovulatory phase and luteal phase, including T2-weighted imaging and BOLD MR imaging. Multi-gradient-recalled echo (MGRE) sequence was used to obtain BOLD MR images. T2* values of different uterine layers, including endometrium, junctional zone and myometrium, on sagittal images were analyzed quantitatively.

RESULTS

Twenty-four subjects calculated T2* values successfully. The T2* values of each zonal structure during menstruation were significantly lower than those during ovulatory phase (P < 0.05) and luteal phase (P < 0.001). The T2* value of junctional zone was significantly lower than that of the myometrium over all three menstrual phases (P = 0.000, menstrual; P = 0.000, ovulatory; P = 0.001, luteal). The mean T2* value in endometrium during the ovulatory phase was the highest of the uterine zones over menstrual cycle. During menstrual phase, there was no statistical difference between endometrium and junctional zone (P > 0.05). Conversely, the comparison of the T2* values between endometrium and myometrium, junctional zone and myometrium both showed significant difference (P = 0.000). The mean T2* values within endometrium during ovulatory phase and luteal phase were significantly higher than those within junctional zone and myometrium (P < 0.05).

CONCLUSIONS

Cyclic changes of T2* values in each zonal structure of the uterus were revealed during the menstrual cycle by means of BOLD technique, which may be potentially beneficial in investigating dysmenorrhea, guiding assisted reproductive technologies and monitoring hypoxia in gynecological tumors.

A mathematical model of maternal vascular growth and remodeling and changes in maternal hemodynamics in uncomplicated pregnancy

The maternal vasculature undergoes tremendous growth and remodeling (G&R) that enables a > 15-fold increase in blood flow through the uterine vasculature from conception to term. Hemodynamic metrics (e.g., uterine artery pulsatility index, UA-PI) are useful for the prognosis of pregnancy complications; however, improved characterization of the maternal hemodynamics is necessary to improve prognosis. The goal of this paper is to develop a mathematical framework to characterize maternal vascular G&R and hemodynamics in uncomplicated human pregnancies. A validated 1D model of the human vascular tree from the literature was adapted and inlet blood flow waveforms at the ascending aorta at 4 week increments from 0 to 40 weeks of gestation were prescribed. Peripheral resistances of each terminal vessel were adjusted to achieve target flow rates and mean arterial pressure at each gestational age. Vessel growth was governed by wall shear stress (and axial lengthening in uterine vessels), and changes in vessel distensibility were related to vessel growth. Uterine artery velocity waveforms generated from this model closely resembled ultrasound results from the literature. The literature UA-PI values changed significantly across gestation, increasing in the first month of gestation, then dramatically decreasing from 4 to 20 weeks. Our results captured well the time-course of vessel geometry, material properties, and UA-PI. This 1D fluid-G&R model captured the salient hemodynamic features across a broad range of clinical reports and across gestation for uncomplicated human pregnancy. While results capture available data well, this study highlights significant gaps in available data required to better understand vascular remodeling in pregnancy.

Mid-luteal uterine artery Doppler indices in the prediction of pregnancy outcome in nulliparous women undergoing assisted reproduction

Traditionally, the assessment of endometrial receptivity at transvaginal ultrasound scan has been based on the thickness and the morphological appearance of the endometrium. The objective of this study was to prospectively evaluate endometrial thickness (ET), endometrial morphology and uterine artery Doppler parameters prior to assisted reproduction treatment (ART) in the prediction of pregnancy outcome. This was a prospective cohort study. ET, morphology and uterine artery Doppler (UtAD) pulsatility index (PI) and resistance index (RI) were measured in the mid-luteal stage of the menstrual cycle ultrasonographically, timed with urinary luteinizing hormone testing. A total of 50 women were included in the analysis. The clinical pregnancy rate (CPR) per embryo transfer was 42.0% (n = 21/50). Twenty nine women (58.0%) had an unsuccessful outcome. There were no differences in mean ± SD endometrial thickness (ET) (10.0 ± 1.8 mm vs. 10.5 ± 2.4; p = 0.43), or endometrial morphology (100% (n = 21) vs 100% (n = 29); p = 1.00) between the pregnant and not pregnant groups. Similarly, there were no differences in mean ± SD UtAD PI (2.17 ± 0.83 vs. 2.07 ± 0.81; p = 0.67 or mean ± SD UtAD RI (0.84 ± 0.10 vs. 0.81 ± 0.10; p = 0.30). Ultrasonographic endometrial assessment did not differentiate between those who would have a subsequent clinical pregnancy.

Effect of Low-Dose Aspirin on Midluteal Phase Uterine Artery Blood Flow in Patients With Recurrent Pregnancy Loss

OBJECTIVES

The purpose of this study was to evaluate differences in uterine artery blood flow parameters and pregnancy outcomes, if any. An investigation was conducted to determine the effects of low-dose aspirin on uterine artery blood flow indices in patients with recurrent pregnancy loss.

METHODS

This observational study included 353 Chinese women with a history of recurrent pregnancy loss and 85 women without a history of recurrent pregnancy loss (control group) from Ren Ji Hospital. All patients were scanned transvaginally with transvaginal Doppler sonography 6 to 8 days after ovulation to measure the pulsatility index (PI), resistive index (RI), and systolic-to-diastolic ratio (S/D) of the left and right main uterine arteries. Low-dose aspirin at a dose of 50 mg/d was administered orally in patients with recurrent pregnancy loss for 2 months, and the blood flow indices were measured subsequently. The Student t test was used for analysis of the results, P < .05 was considered significant.

RESULTS

The mean PI and S/D of the uterine arteries in the recurrent pregnancy loss group were significantly higher than in the control group. Although not statistically significant, the RI was higher in the recurrent pregnancy loss group than the control group. Moreover, the PI and S/D increased as the number of pregnancy losses increased. Significant enhancements of the PI and S/D were observed in patients with 4 or more consecutive abortions. After low-dose aspirin supplementation, patients with recurrent pregnancy loss showed a highly significant reduction in the PI and S/D.

CONCLUSIONS

Uterine blood flow decreased during the luteal phase in patients with recurrent pregnancy loss. Low-dose aspirin induced a reversible increase in uterine blood flow and may be of therapeutic value.

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.

Application of Doppler Ultrasonography in Cattle Reproduction

The development of Doppler processing extended the scope of sonographic imaging from an anatomical to a physiological basis. This technique became established as a clinical tool in human gynaecology. For example, it has been discussed that the implantation of an embryo is influenced by the uterine blood flow. In cows, this uterine blood flow was investigated, using surgically implanted Doppler ultrasonic or electromagnetic blood flow probes prior to the introduction of colour Doppler sonography in bovine medicine. Therefore, the aims of our studies were to use transrectal Doppler sonography for the non-invasive measurement of uterine and ovarian blood flow in cows and to determine changes in genital perfusion during the oestrous cycle, pregnancy and puerperium, respectively. The results of our studies show that transrectal flow imaging can be used to obtain blood flow velocity waveforms from the uterine arteries at any time during the oestrous cycle, pregnancy and puerperium. During all these phases, characteristic changes in the uterine blood flow could be observed. This uterine blood flow was low during diestrus and high during proestrus and oestrus. During pregnancy, an exponential rise in uterine blood supply could be detected. There was a positive relationship between the uterine blood flow volume (BFV) at the end of gestation and the birth weight of calves. During puerperium, the uterine BFV declined tremendously, especially during the first week after birth. In cows, with pathological disturbances of the pueperium a delayed decrease in the uterine BFV was observed. Characteristic alterations occurred also in the luteal blood flow during the oestrous cycle, which were highly related to those of the progesterone levels. Furthermore, it has been detected by the colour Doppler technique that there is no decrease, but an increase of the luteal blood flow at the beginning of luteolysis in cows. Another group has found that there are close relationships between the LH-surge and the follicular blood flow before ovulation. In conclusion, these studies show that transrectal colour Doppler sonography is a useful technique for the investigation of the genital blood flow and provides new information about physiological changes of the genital organs during, all reproductive phases. The influence of the genital blood flow on fertility in cows needs to be examined further in future studies.

Ultrasound and the receptivity of the endometrium

Ultrasound imaging can be used to assess the endometrium in a number of ways. In particular, time-lapse video recordings can show that the lining of the uterus undergoes rhythmical contractions that vary in strength and intensity throughout the ovarian cycle. These contractions appear to assist in sperm transport at the time of ovulation, but can decrease the chances of a fertilized egg implanting in the uterus if they persist later in the cycle. They are also the cause of ectopic pregnancies occurring in IVF treatment cycles. In order to reduce these uterine contractions and therefore increase the chances of a successful uterine pregnancy, IVF treatment cycles should incorporate minimal stimulation so as to make them as close to natural cycles as possible.

Is there a role for preparatory cycle in ovum donation recipients?

PURPOSE OF REVIEW

In ovum donation cycles, the role of preparatory cycles to ensure proper endometrial development in the recipient remains controversial. As evidenced in the literature, endometrial receptivity is critical in conception. Therefore, endometrial preparation with exogenous hormones in addition to synchronization of the recipient and donor are essential in achieving a successful outcome.

RECENT FINDINGS

There are very limited data specifically examining the benefit of recipients undergoing preparatory cycles prior to their actual egg donation cycle. One study concluded that trial hormone replacement treatment cycles with endometrial biopsies may be useful in older reproductive-age women but not in younger women. Another study showed no difference in pregnancy rates between those who did and did not undergo preparatory cycles.

SUMMARY

Since one of the integral elements of preparatory cycles is determining endometrial dating, with relatively conflicting data, these mock cycles may not be as beneficial as expected. Therefore, for those who routinely use preparatory cycles, the potential risks, benefits, and costs of these cycles, increased hormonal exposure, the relatively invasive nature of the procedure, and time prior to performing them must be considered.

Uterine effects of metformin administration in anovulatory women with polycystic ovary syndrome

BACKGROUND

Metformin has been shown to improve fertility in anovulatory patients with polycystic ovary syndrome (PCOS), inducing not only a high ovulation and pregnancy rate but also reducing the incidence of miscarriages. The aim of the present study was to evaluate the uterine effects of metformin in patients with PCOS who ovulated under metformin.

METHODS

Thirty-seven non-obese primary infertile anovulatory patients with PCOS and another 30 age- and body mass index-matched healthy women (control group) were studied. PCOS patients were treated with metformin (850 mg twice daily) for 6 months, whereas the control group did not receive any treatment. In these PCOS patients who ovulated whilst under metformin treatment (PCOS group) and in controls, uterine, sub-endometrial and endometrial blood flow, and endometrial thickness and pattern were evaluated using serial ultrasonographic assessments.

RESULTS

Before treatment, uterine, sub-endometrial and endometrial blood flows were significantly lower in patients with PCOS than in the control group. All indexes of uterine vascularization were significantly improved in the PCOS group with metformin treatment and were not different from the controls. Nor was any difference in endometrial thickness and pattern detected between PCOS and control groups. After grouping the data of PCOS patients who ovulated under metformin for cycles with favourable/unfavourable reproductive outcome, no difference in any parameter was observed.

CONCLUSIONS

Metformin improves all surrogate markers of endometrial receptivity in PCOS patients, without difference between patients who had favourable or unfavourable reproductive outcome.

Endometrial evaluation in superovulation programs: relationship with successful outcome

It is well known that an adequate endometrial receptivity is required for successful implantation in both natural and assisted reproductive cycles. In particular, a brief "implantation window", during which endometrium undergoes anatomical and molecular changes necessary for embryo implantation, has been observed. The hormonal treatment applied to induce ovulation seems to be able to modify the normal development of the prenidatory endometrium, with possible negative effect on the implantation rate. For this reason, several attempts have been made to identify specific markers of endometrial receptivity, useful for predicting implantation outcome in clinical practice. Even if different histological, immunohistochemical, and ultrasonographic parameters are studied, none unfortunately has been univocally shown to be predictive of pregnancy outcome. Therefore, the evaluation of endometrial receptivity remains a challenge in clinical practice.

Influence of hormonal stimulation on in vitro fertilization/embryo transfer outcome

OBJECTIVE

To compare efficacy and efficiency of ovarian stimulation therapy.

STUDY DESIGN

Retrospective study compares ovarian response as number of retrieved oocytes, fertilization rates, endometrial patterns, number of pregnancies and pregnancy rates to different stimulation protocols.

RESULTS

The least number of cancelled cycles was in long protocols with buserelin. There was no difference in overall number of retrieved oocytes between the rFSH and HMG protocols, but 75% of the patients undergoing both protocols had higher number of oocytes after rFSH. The highest pregnancy rate (35.13%) was with rFSH. There was no statistical correlation between endometrial pattern and type of protocol used. Data showed the 9 mm cut-off value for endometrial thickness, and RI = 0.58 for subendometrial blood flow between the pregnant and non-pregnant group of patients. Nitriderm patches significantly decreased (P < 0.05) subendometrial RI of the patients with impaired uterine perfusion, increased endometrial thickness and achieved better morphology.

CONCLUSIONS

These findings demonstrate that rFSH alone and in long protocol gives better results in wide patient population. Nitriderm patches seem to have good impact on pregnancy rate, but further studies are necessary before making any statements.

Acute efficacy of a sublingual dose of nifedipine on uterine arterial blood flow: preliminary data in prematurely menopausal women

OBJECTIVES

To determine whether the calcium blocker nifedipine alters Doppler velocimetry and impedance parameters in the uterine artery in prematurely menopausal women.

METHODS

Uterine artery Doppler examinations were performed transvaginally in seventeen prematurely menopausal women without the use of calcium blocker (T0). Following a 10-mg sublingual dose of nifedipine patients were subsequently rescanned at successive time intervals (T25 = 25, T40 = 40, T60 = 60 min). PI (normalized (NPI) for heart rate) and maximum, minimum and average velocities of the uterine artery were recorded and waveforms were qualitatively assessed using Goswamy and Steptoe's waveform classification.

RESULTS

Quantitative analysis showed a significant decrease in NPI at T(25) in the right and left uterine arteries (T0: PI = 2.95 and 3.01; T25: PI = 1.52 and 1.52, respectively; P < 0.001) and until the end of the experiment. Minimum and average blood flow velocities increased strongly (P < 0.001) whereas the maximum velocities did not change significantly (P = 0.12). Qualitative analysis revealed more conspicuous results: eight subjects presented 'abnormal' spectra: one was type A (absence of protodiastole), three were type B (absence of telediastole) and four were type O (no diastolic blood flow); all of them recovered type C waveforms (normal spectrum) during the hour following nifedipine administration.

CONCLUSIONS

Nifedipine induces a reversible decrease in NPI and an increase in blood flow velocities in the uterine artery in prematurely menopausal women. These results suggest that nifedipine is a potent uterine arterial vasodilator.

Role of utero–ovarian vascular impedance: predictor of ongoing pregnancy in an IVF–embryo transfer programme

The objective of this study was to evaluate the role of uterine, endometrial and follicular blood flow in prediction of ongoing pregnancy after assisted conception. A prospective observational study was conducted on 53 women undergoing IVF treatment. Transvaginal colour and pulsed Doppler measurements were performed on the day that pituitary suppression was confirmed, on day 10 of ovarian stimulation and on the day prior to human chorionic gonadotrophin injection. On the last day of ovarian stimulation, blood flow in the ascending uterine artery of the women who would conceive was characterized by significantly lower pulsatility index values. Sub-endometrial vascular impedance was comparable in the pregnant and non-pregnant groups. There were no differences in the perifollicular vascularity between pregnant and non-pregnant women. The chance of achieving pregnancy predicted by uterine artery Doppler and perifollicular blood flow in women whose PI values were higher than 3.26 and 1.08 was very low, with a sensitivity of 1.00 and specificity of 0.59 and 0.82 respectively. The data provide evidence for an association between utero-ovarian perfusion and reproductive outcome following IVF treatment. Uterine and ovarian vascular impedance values identify those women whose pregnancy chances are significantly limited. Measures to decrease vascular impedance in such women might enhance pregnancy rates by improving embryo quality and uterine receptivity for implantation.

Transrectal Doppler sonography of uterine blood flow during early pregnancy in mares

Transrectal color Doppler sonography was used for the noninvasive investigation of uterine blood flow in five mares. Both the left and right uterine arteries were scanned to obtain blood flow velocity waveforms during two consecutive estrous cycles and two early pregnancies in each mare. Blood flow was expressed as the time-averaged maximum velocity (TAMV) and the resistance index (RI). In all pregnancies the embryonic vesicle could be detected for the first time on Day 11 (day of ovulation: Day 0). No differences in mean TAMV and RI values of both uterine arteries were observed in comparison to the corresponding days of the estrous cycle until Day 11 of pregnancy (P>0.05). From Day 11 onwards, mean TAMV values were higher and mean RI values lower in pregnant mares than in cyclic mares (P<0.05). During the estrous cycle TAMV and RI values did not differ between the right and left uterine arteries (P>0.05). From Days 15 to 29 of pregnancy, TAMV values were consistently higher and RI values lower in the uterine artery ipsilateral to the conceptus and they had a more distinct rise and decline, respectively, compared to the contralateral uterine artery (P<0.05). The variance component estimates for the effect of mare on TAMV and RI values during pregnancy were 60 and 53%, respectively, and for the effect of day of pregnancy, they were 29 and 34%, respectively (P<0.0001). Within mares there were no significant differences between the two pregnancies with regard to blood flow (P>0.05). The results show that uterine blood supply increases in mares during the second week of pregnancy compared to cyclic mares. Furthermore there are individual variations in blood flow between mares.

Ultrasonography as a predictor of embryo implantation after in vitro fertilization: a controlled study

OBJECTIVE

To investigate the predictive value of ultrasonographic parameters as prognostic indicators of implantation after IVF when measured on the day of embryo transfer.

DESIGN

Comparative, observational study.

SETTING

University teaching hospital.

PATIENT(S)

Two hundred eighty patients undergoing IVF.

INTERVENTION(S)

Ovarian stimulation, IVF.

MAIN OUTCOME MEASURE(S)

Variables related to patients' clinical characteristics, treatment characteristics, ovarian response, ovum retrieval, outcome of IVF and ICSI, embryo transfer, ultrasonographic and Doppler endometrial measurements, and uterine blood flow that have been proposed as potential predictive factors of implantation. All transvaginal ultrasonographic assessments were performed on the day of embryo transfer.

RESULT(S)

Among 240 patients finally evaluable, 67 (group 1) became pregnant after IVF, and 173 (group 2) failed to conceive. The 111 nonpregnant patients who had the same embryo score per replacement (group 3) as did patients in group 1 were selected for comparison purposes. The only significant differences between groups 1 and 3 were the type A endometrium and the absence of a protodiastolic notch in the uterine arteries, both of which were more frequently found in group 1. However, a considerable overlap existed between conception and nonconception cycles regarding both variables.

CONCLUSION(S)

Ultrasonographic parameters as predictors of implantation in assisted reproduction have a limited value in the clinical setting.

Cycle-to-cycle variation in utero-ovarian hemodynamic indices in ovarian stimulation and natural cycles of the same women and its effect on the outcome of assisted reproduction treatment

OBJECTIVE

To investigate the blood flow parameters between cycles of the same women to assess whether parameters predicting a successful pregnancy in a stimulation cycle could be used to determine the outcome of subsequent natural cycles.

DESIGN

A prospective study.

SETTING

Assisted reproduction unit, the University of Hong Kong.

PATIENT(S)

Fifty-eight IVF cycles and 40 natural cycles were evaluated.

INTERVENTION(S)

Assessments of the utero-ovarian pulsatility indices (PIs), resistance indices (RIs), and endometrial color signals.

RESULT(S)

In IVF cycles, the pregnancy rate (27%) was similar to that in frozen-thawed embryo transfer (FET) (28%) cycles. The utero-ovarian PIs and RIs in IVF cycles were significantly lower than those in the natural cycles. There was a significant correlation between the uterine PI in stimulation cycles and that in natural cycles. In IVF cycles, the pregnancy rate declined significantly when the uterine PI was >2.70 and the RI was >0.9. In FET cycles, no decline in pregnancy rate was seen. Conceptional FET cycles showed significantly higher uterine PI, uterine RI, and endometrial color signals compared with conceptional IVF cycles.

CONCLUSION(S)

Hemodynamic parameters in stimulation cycles are different from those in natural cycles, and the values of various parameters in predicting pregnancy are also different.

The antiandrogenic effect of flutamide improves uterine perfusion in women with polycystic ovary syndrome

OBJECTIVE

To evaluate whether, by blocking androgen action, flutamide can decrease and normalize vascular resistance in the uterine artery in patients with polycystic ovary syndrome (PCOS).

DESIGN

Prospective and controlled study.

SETTING

Endocrinological Centre of the Department of Obstetrics and Gynecology of the University of Cagliari, Italy.

PATIENT(S)

Twenty-two patients with PCOS were enrolled in the study and randomly assigned to one of the following two treatments for 3 months: oral administration of flutamide (250 mg twice daily) or placebo.

INTERVENTION(S)

Doppler flow measurement of the uterine artery and serum hormone concentration determination during the early follicular phase of the menstrual cycle before treatment and during the third month of treatment.

MAIN OUTCOME MEASURE(S)

Pulsatility index (PI) of the uterine artery before and during treatment.

RESULT(S)

The PI of the uterine artery decreased significantly during treatment. No difference was found in patients treated with placebo. Correlation was found only between the PI values of the uterine artery and DHEAS.

CONCLUSION(S)

The low uterine perfusion that characterizes patients with PCOS can be improved by the antiandrogenic effect of flutamide.

In vitro fertilization in spontaneous cycles--our experience

OBJECTIVE

To study the efficacy of a simple protocol of natural cycle in vitro fertilization.

METHOD

A retrospective study of 59 natural treatment cycles in 37 infertile couples with previous unsuccessful attempts of conventional in vitro fertilization.

RESULTS

In 24% of cycles, the aspiration was cancelled because of inadequate visualization of follicles or because of preterm ovulation. Aspiration was performed in 45 cycles with oocyte retrieval of 82% per aspiration. Embryo transfer was performed in 30 cycles, pregnancy rate per pick-up was 15%.

CONCLUSION

In vitro fertilization in a natural cycle is a simple, relatively cheap and comfortable procedure with reasonable results and can be offered to patients scheduled not only for in vitro fertilization because of tubal factor but also to patients with endometriosis or unexplained infertility.

Doppler ultrasound examination of uterine arteries on the day of oocyte retrieval in patients with uterine fibroids undergoing IVF

BACKGROUND

There is no consensus as to whether uterine fibroids have any adverse effects on the outcomes of assisted reproduction treatment. This prospective study compared implantation/pregnancy rates of women with and without fibroids undergoing IVF-embryo transfer and measured uterine blood flow indices of the fibroid group.

METHODS

Patients who had fibroids that, during transvaginal scanning, were found to be not distorting the endometrial lining were placed in the fibroid group, while patients with normal uteri were controls. Those with previous myomectomy or pedunculated subserosal fibroids only were excluded. All received a standard ovarian stimulation regimen. Doppler ultrasound examinations of uterine arteries were carried out in the fibroid group prior to oocyte retrieval.

RESULTS

Similar implantation/pregnancy rates, multiple pregnancy rates and pregnancy outcomes were noted in both groups. In the fibroid group, significantly lower pulsatility index (PI) and resistance index (RI) of the right uterine artery and the average of right and left uterine arteries were found in those failing to conceive than in those patients who subsequently conceived (P < 0.001).

CONCLUSION

The presence of fibroids not distorting the endometrial lining does not adversely affect implantation and pregnancy rates during IVF-embryo transfer. Significantly lower uterine artery PI and RI were found in non-pregnant women with fibroids than in their pregnant counterparts.

Measurement of endometrial tissue blood flow: a novel way to assess uterine receptivity for implantation

OBJECTIVE

To assess endometrial receptivity in terms of endometrial tissue blood flow (ETBF) measured hysterofiberscopically by laser blood-flowmetry, and to examine the technique's effectiveness in an in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) program.

DESIGN

A prospective clinical study.

SETTING(S)

IVF program in a university hospital.

PATIENT(S)

A total of 75 infertile women with normal menstrual cycles undergoing IVF/ICSI.

INTERVENTION(S)

ETBF, conventional ultrasonographic, endocrinologic, and histologic parameters for receptivity and immunoreactivity for vascular endothelial growth factor (VEGF) in endometrium were assessed between days 4 and 6 of the luteal phase in a spontaneous menstrual cycle. Then all patients underwent IVF/ICSI.

MAIN OUTCOME MEASURE(S)

Achievement of clinical pregnancy by IVF/ICSI.

RESULT(S)

ETBF, VEGF expression, and the number of embryos were significantly higher in the women who became pregnant than in those who did not. By stepwise multiple logistic regression, significant predictors of pregnancy were the number of embryos and ETBF but not conventional receptivity markers. The rate of pregnancy was significantly higher in women with ETBF values of at least 29 mL/min per 100 grams of tissue than in women with lower values (42 vs. 15% in 36 and 39 women, respectively). ETBF was significantly greater in morphologically normal than abnormal uteri. In normal uteri, ETBF was greatest in the fundus. Correspondingly, in normal uteri 85% of gestational sacs were implanted in the fundus.

CONCLUSION(S)

ETBF is superior to conventional parameters for determining endometrial receptivity for implantation.

Uterine perfusion and hormonal pattern in patients with polycystic ovary syndrome

PURPOSE

To evaluate whether polycystic ovary syndrome (PCOS) patients with different pulsatility index (PI) of uterine artery showed differences in their hormonal pattern.

METHODS

Eighty-eight PCOS-affected patients and 15 controls were submitted to Doppler flow measurement of uterine artery; LH, FSH PRL, estradiol, and androgens concentration determination; and BMI evaluation during early follicular phase.

RESULTS

The mean PI of uterine artery of PCOS patients was significantly higher than control group (2.97 +/- 0.9 vs. 1.89 +/- 0.2 respectively). The distribution of the PI'values was significantly different in the PCOS-affected patients and in control group. The plasma levels of DHEAS and BMI were significantly higher in PCOS patients with PI > or = 3 than in PCOS patients with PI < 3.

CONCLUSION

High resistance in the uterine artery is present in PCOS patients, but a wide range PI values of uterine artery is present. BMI and DHEAS seem to be factors interfering with uterine perfusion.

Haemodynamic evaluation of tubal and male factors of infertility in natural and ovarian stimulation cycles

PURPOSE

To determine the haemodynamic parameters in women with tubal and male factors of infertility and to investigate the effect of ovarian stimulation on the blood flow indices of the uterine and ovarian arteries.

METHODS

Prospective evaluation of the pulsitility index (PI) and resistance index (RI) of the uterine and ovarian arteries in the tubal and male factors of infertility was done. Comparisons were made between the natural and ovarian stimulation cycles.

RESULTS

In natural cycles, uterine PI was 3.55 +/- 1.39 and RI was 0.95 +/- 0.05 in tubal infertility. These were significantly lower (uterine PI = 4.13 +/- 0.08; uterine RI = 0.99 +/- 0.06) than the corresponding indices in patients with male factor infertility. After ovarian stimulation in tubal factor, uterine PI and RI were 2.62 +/- 0.73 and 0.88 +/- 0.08 and were similar (PI = 2.55 +/- 0.62, RI = 0.87 +/- 0.06) to male factor infertility.

CONCLUSIONS

The data points to measurable differences in the uterine PI and RI between the tubal infertility and male infertility in the natural cycles. These differences were abolished after ovarian stimulation.

Doppler evaluation of the uterine and spiral arteries from different sampling sites and phases of the menstrual cycle during controlled ovarian hyperstimulation

OBJECTIVE

To compare the pulsatility index (PI) and resistance index (RI) at different sampling sites of the uterine and spiral arteries in the early and mid-menstrual phases.

MATERIALS AND METHODS

The uterine and spiral arteries of 110 women undergoing similar ovarian hyperstimulation and intra-uterine insemination regimes were examined using transvaginal color Doppler ultrasound. The uterine artery was sampled at five sites: (1) ascending branch; (2) descending branch; (3) proximal, near branch division; (4) mid, 0.5 cm distal to the division; (5) lateral location, 1 cm distal to the division. The spiral artery was sampled at three sites: (a) anterior; (b) fundal; (c) posterior. The uterine and spiral arteries were examined twice, on days 2-3 and 14-16, respectively, of the menstrual cycle. The women were also grouped according to age at examination, < or = 30 years and > 30 years. The PI and RI values for different sites, menstrual phase, and age were compared.

RESULTS

The mean PI and RI values of the uterine artery were: (1) 2.86 +/- 1.20 and 0.92 +/- 0.13; (2) 2.66 +/- 1.15 and 0.89 +/- 0.12; (3) 2.88 +/- 1.26 and 0.90 +/- 0.15; (4) 3.03 +/- 1.02 and 0.91 +/- 0.07; (5) 3.23 +/- 1.38 and 0.89 +/- 0.12; and of the spiral artery were (a) 1.61 +/- 1.01 and 0.69 +/- 0.17; (b) 1.69 +/- 0.74 and 0.74 +/- 0.17; (c) 1.73 +/- 0.86 and 0.68 +/- 0.17. The PI values for uterine and spiral arteries at two phases of the menstrual cycle were 2.92 +/- 1.18 and 1.55 +/- 0.72 (days 2-3); 3.11 +/- 1.15 and 1.80 +/- 1.02 (days 14-16), respectively; for younger women (age < or = 30 years) these values were 2.83 +/- 1.22 and 1.6 +/- 0.85 and for older women (age > 30 years) 3.0 +/- 1.34 and 1.72 +/- 0.96, respectively.

CONCLUSIONS

There were no significant differences in PI and RI values of the uterine and spiral arteries at different sampling sites, phase of the menstrual cycle or age. The higher PI values tended to occur in the lateral uterine artery and posterior spiral artery, during the mid-menstrual phase and in the older age group. The PI and RI values of the mid-uterine and fundal spiral artery sampling sites are representative of the whole uterine artery and spiral artery, respectively.

Predicting the histologic dating of an endometrial biopsy specimen with the use of Doppler ultrasonography and hormone measurements in patients undergoing spontaneous ovulatory cycles

OBJECTIVE

To examine the relation between uterine blood flow and endometrial thickness on transvaginal Doppler ultrasonography, serum E2 and progesterone levels, and the histologic dating of an endometrial biopsy specimen obtained in the midluteal phase of a spontaneous cycle.

DESIGN

Prospective clinical study.

SETTING

A tertiary care infertility center.

PATIENT(S)

One hundred fifty-nine patients with normal menstrual cycles.

INTERVENTION(S)

Transvaginal Doppler ultrasonographic evaluation of uterine blood flow and endometrial thickness, determination of serum concentrations of E2 and progesterone, and endometrial biopsy.

MAIN OUTCOME MEASURE(S)

Resistance index, pulsatility index, serum E2 and progesterone levels, endometrial thickness, and histologic dating of the endometrium.

RESULT(S)

One hundred thirteen (71%) of the endometrial biopsy specimens showed complete secretory transformation and thus were classified as "in phase," and 46 (29%) of the specimens lacked some or all of the criteria for secretory transformation and thus were classified as "out of phase." There was no statistically significant difference between the in phase and out of phase groups with regard to patient age, endometrial thickness, serum hormone levels, or resistance index. The pulsatility index was significantly higher in the in phase group. The overall predictive value of the studied parameters was only 64% (sensitivity, 57%; specificity, 66%).

CONCLUSION(S)

Doppler ultrasonographic evaluation of uterine blood flow and measurement of hormone concentrations cannot be used to predict the histologic dating of an endometrial biopsy specimen obtained in the midluteal phase of a spontaneous cycle.

Association of endometrial blood flow as determined by a modified colour Doppler technique with subsequent outcome of in-vitro fertilization

An endometrial thickness of 10 mm or more has been reported to be favourable for embryo implantation. Nevertheless, many women participating in in-vitro fertilization (IVF) programmes have adequate endometrial thickness but do not achieve satisfactory implantation. With the aid of power Doppler sonography, we examined the association between intra-endometrial vascularity and reproductive outcome. For this study, we enrolled only women with endometrial thickness >/=ISOdia>/=10 mm and excluded those with apparent endometrial pathologies. Of 95 women undergoing IVF cycles, there resulted 37 intrauterine pregnancies. The women were of similar age, body mass index, peak oestradiol concentration and endometrial thickness, and a similar number of embryos were transferred. Those women with an intra-endometrial power Doppler area (EPDA) <5 mm2 achieved a significantly lower pregnancy rate (23. 5 versus 47.5%, P = 0.021) and implantation rate (8.1 versus 20.2%, P = 0.003) than those with an EPDA >/=ISOdia>/=5 mm2. We conclude that, in addition to endometrial thickness, EPDA may serve as a factor indicative of endometrial receptivity. Women with adequate endometrial thickness but a small EPDA tended to have an unfavourable reproductive outcome.

Effect of chronic administration of cabergoline on uterine perfusion in women with polycystic ovary syndrome

OBJECTIVE

To confirm whether patients with polycystic ovary syndrome (PCOS) have a reduction in uterine perfusion and to verify whether chronic administration of cabergoline can decrease this high vascular resistance.

DESIGN

Prospective randomized trial.

SETTING

Endocrinological Centre of the Department of Obstetrics and Gynecology, University of Cagliari, Cagliari, Italy.

PATIENT(S)

Thirty patients were enrolled in the study: 20 affected by PCOS and 10 healthy controls. Patients with PCOS were randomly assigned to one of two treatments for 3 months: oral administration of cabergoline (0.5 mg) every week or oral administration of placebo every week.

INTERVENTION(S)

All patients underwent transvaginal ultrasonography associated with Doppler flow measurement of the uterine artery, and serum hormone concentrations were determined during the early follicular phase. In women with PCOS, Doppler flow measurement and hormonal assessment were repeated in the early follicular phase of the third month of treatment.

MAIN OUTCOME MEASURE(S)

Pulsatility index of the uterine artery before and during treatment.

RESULT(S)

The mean pulsatility index of the uterine artery in patients with PCOS was significantly higher than that of the control group (3.29+/-0.5 and 2.01+/-0.2, respectively). Patients with PCOS treated with cabergoline showed a significant increase in uterine perfusion, with a pulsatility index of 3.14+/-0.6 before and 2.39+/-0.5 during the treatment. No difference was found in patients with PCOS treated with placebo.

CONCLUSION(S)

Patients with PCOS have high resistance in the uterine arteries, but chronic administration of cabergoline can increase uterine perfusion.

The predictive value of uterine artery blood flow measurements for uterine receptivity in an intracytoplasmic sperm injection program

OBJECTIVE

To assess whether uterine artery blood flow impedance, measured as the pulsatility index on the day of ET in patients undergoing IVF-ET with microinjection, can predict the likelihood of pregnancy.

DESIGN

Prospective clinical study.

SETTING

A tertiary referral center for assisted reproduction.

PATIENT(S)

Seventy patients undergoing intracytoplasmic sperm injection (ICSI) for andrologic indications.

INTERVENTION(S)

Transvaginal color Doppler examination performed on the day of ET.

MAIN OUTCOME MEASURE(S)

Mean (+/- SD) pulsatility index value of the left and right uterine arteries, serum E2 levels, implantation rates, and ongoing pregnancy rates (PRs).

RESULT(S)

The patients were divided into pregnant and nonpregnant groups and were separated according to whether the pulsatility index was low (1.00-1.99), medium (2.00-2.99), or high (> or = 3.00). The pulsatility index values did not change statistically in the pregnant and nonpregnant groups. The implantation rates were 19.5%, 15.4%, and 25% for the low-, medium-, and high-pulsatility index groups, respectively. The ongoing PRs for the same groups were 35.3%, 26.7%, and 37.5%, respectively.

CONCLUSION(S)

The study suggests that blood flow, measured as the pulsatility index on the day of ET, cannot predict the likelihood of pregnancy in stimulated cycles of ICSI.

Evidence of interplay between plasma endothelin-1 and 17 beta-estradiol in regulation of uterine blood flow and endometrial growth in infertile women

OBJECTIVE

To determine the effects of gonadotropin-induced ovarian stimulation on the plasma levels of endothelin-1 as well as on uterine blood flow and endometrial thickness.

DESIGN

Controlled cross-over clinical study.

SETTING

Academic research environment.

PATIENT(S)

Eighteen volunteer infertile women (31.4 +/- 2.5 years, mean +/- SE) participating in an IVF-ET program.

INTERVENTION(S)

Transvaginal Doppler ultrasound was performed and blood samples were collected 4 days after the LH surge in a spontaneous cycle and 4 days after hCG administration in a subsequent gonadotropin-stimulated cycle.

MAIN OUTCOME MEASURE(S)

Plasma levels of E2, P, and endothelin-1; uterine artery pulsatility index; and endometrial thickness.

RESULT(S)

Stimulated cycles were associated with significantly higher E2 levels (101.0 +/- 10.2 versus 723.5 +/- 57.3 pg/mL [conversion Factor to SI unit, 3.671]; spontaneous versus stimulated), thicker endometrium (9.2 +/- 2.5 versus 11.4 +/- 2.9 mm), and lower endothelin-1 levels (2.5 +/- 0.1 versus 2.1 +/- 0.1 pg/mL [conversion factor to SI unit, 0.4]) and pulsatility index (3.22 +/- 0.12 versus 2.63 +/- 0.08) than spontaneous cycles. Endothelin-1 correlated negatively with E2 (r = -0.38), but not with P or pulsatility index. Differences in endothelin-1 and endometrial thickness between spontaneous and stimulated cycles correlated negatively (r = -0.56) with each other.

CONCLUSION

Our results suggest an inhibitory role for E2 in the release of endothelin-1, which could be a factor in the regulation of uterine and endometrial blood flow.