Comparison of uterine and spiral artery blood flow in women with unexplained and tubal infertility

The definition of unexplained infertility: A systematic review

BACKGROUND

There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice.

OBJECTIVES

This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis.

SEARCH STRATEGY

CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language.

DATA COLLECTION AND ANALYSIS

Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range.

MAIN RESULTS

Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies.

CONCLUSIONS

This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

Arterial Blood Supply of the Mesosalpinx Appears Segmentally Organized in Absence of Uterine Tubes Arteries

Arterial branches to the uterus and ovaries that pass through the mesosalpinx contribute significantly to the maintenance of the ovarian reserve. Especially arterial supply of the uterine tube is provided by a number of anastomoses between both the uterine and ovarian vessels. Knowledge on the morphologic peculiarities will allow to identify main contributors especially blood flow ultrasound examination for the purpose of ovary preserving surgery. This study aimed at identifying landmarks especially for so-called low-flow tubal vessels. Arteries of 17 female Thiel-embalmed bodies were studied along three preselected paramedian segments and measurements taken. A section was made through the center of the ovary perpendicular to uterine tube, then the mesosalpinx tissue distance was divided into 3 equivalent zones: upper, middle and lower thirds. The surface area of the mesosalpinx averaged 1088 ± 62 mm2. 47.7 ± 7.1 % of the mesosalpinx zones included macroscopically visible vessels. The lower third segment of mesosalpinx was the thickest averaging 2.4 ± 1.5 mm. One to three tubal branches were identified in the middle third of the mesosalpinx. Arterial anastomoses were found in the upper segment of the mesosalpinx, but no presence of a marginal vessel supplying the fallopian tube could be found. Statistically significant moderate positive correlations were established between the diameters of the mesosalpingeal arteries between the three zones. The mesosalpinx, uterine tube and the ovary form areas of segmental blood supply. Variants of tubal vessels appear to be a sparse source of blood supply.

Does low-dose aspirin improve pregnancy rate in women undergoing frozen-thawed embryo transfer cycle? A pilot double-blind, randomized placebo-controlled trial

AIM

To evaluate the effect of adjuvant low-dose aspirin therapy on clinical pregnancy rate and uterine perfusion in women undergoing frozen-thawed embryo transfer (FET) cycles.

METHODS

This study was performed as a pilot randomized, double-blind placebo-controlled trial, from May 2012 to February 2015. Overall, 60 available eligible women who were candidates for FET were randomly assigned to two groups receiving either 100 mg oral aspirin (n =30) or placebo (n =30). The primary outcome measure was clinical pregnancy rate. Secondary outcome measures were pulsatility index (PI), resistance index (RI), implantation rate, live birth rate and miscarriage rate.

RESULTS

There was no significant difference in endometrial thickness, PI and RI. However, the study group had higher rates of clinical pregnancy, implantation, live birth (P = 0.042, P = 0.031 and P = 0.007, respectively) and lower rate of miscarriage (P = 0.020) as compared to the control group. Twin birth rate was comparable between the two groups.

CONCLUSION

Our pilot study demonstrated that administration of low-dose aspirin in FET cycles results in better pregnancy, implantation and live birth rates without changing the uterine hemodynamics or endometrial thickness. However, further randomized clinical studies in larger populations are needed to confirm these findings.

A comparative analysis of arterial blood flow in unexplained infertility, tubal infertility and fertile groups

We aimed to compare ovarian (O), uterine (U) and spiral (S) artery (A) resistance of patients diagnosed as fertile, unexplained infertility (UI) and tubal factor infertility (TFI) in the peri-implantation period and independent from the impact of the treatment. UI (n = 70), TFI (n = 75) and fertile (n = 72) patients' ovarian, uterine and spiral artery pulsatility index (PI), resistance index (RI) and the endometrial thickness, serum estradiol and progesterone levels were compared. The specificity and sensitivity values were calculated according to determined cutoff values. Both TFI and control groups' UA PI values were significantly lower than the UI group's PI values. The highest UA RI values were found in UI group and the lowest values were in the control group. UI and TFI groups' OA PI/RI values were significantly higher than the control group. Both the control and TFI groups' SA PI/RI values were significantly lower than UI group's PI/RI values. UI patients' uterine and spiral arteries PI values >1.86 and >0.85, RI values >0.80 and >0.53 can be used as a valuable test showing reduced uterine perfusion. Ovarian artery PI values  >0.96 and RI values  >0.58 can be used as tests showing decreased ovarian perfusion in patients with TFI. In these patients, embryo cryopreservation can be considered.

Doppler study of uterine hemodynamics in women with unexplained infertility

OBJECTIVE

To evaluate uterine artery blood flow using pulsed Doppler, and endometrial and subendometrial microvascularization using three-dimensional (3D) power Doppler, in women with unexplained infertility.

STUDY DESIGN

In a prospective clinical trial at a university teaching hospital, 40 women with unexplained infertility were compared to 40 fertile parous controls. In the mid-luteal (peri-implantation) phase, the endometrial thickness and volume, uterine artery pulsatility index (PI) and resistance index (RI), endometrial and subendometrial 3D power Doppler vascularization index (VI), flow index (FI), and vascularization flow index (VFI), and serum estradiol and progesterone levels were measured in both groups.

RESULTS

The uterine artery PI (P = 0.003) and RI (P = 0.007) were significantly increased and the endometrial VI (P = 0.029), FI (P = 0.031), and VFI (P = 0.001) and subendometrial VI (P = 0.032), FI (P = 0.040), and VFI (P = 0.005) were significantly decreased in the unexplained infertility group. The endometrial thickness and volume and serum estradiol and progesterone levels, however, were not significantly different between the two groups.

CONCLUSION

Peri-implantation endometrial perfusion is impaired in women with unexplained infertility: Doppler study of uterine hemodynamics should therefore be considered in infertility work-up.

Effect of metformin treatment on endometrial vascular indices in anovulatory obese/overweight women with polycystic ovarian syndrome using three-dimensional power doppler ultrasonography

PURPOSE

Metformin has been shown to be an effective treatment for anovulatory polycystic ovary syndrome (PCOS) patients in terms of menstrual cyclicity, ovulation, and pregnancy, as well as reduction of early miscarriage rate. The aim of the study is to assess the effect of metformin on the endometrial vascular indices in anovulatory obese PCOS women using three-dimensional power Doppler sonography (3DPDUS).

METHODS

A prospective study was set to determine the beneficial effects of metformin on PCOS patients. Fifty anovulatory obese PCOS patients were compared with another 50 healthy volunteers who were age- and body mass index-matched (control group). PCOS patients were treated with metformin (Glucophage; MerckSerono) 850 mg 3 times a day for 6 months. Assessment of the endometrial thickness and volume, uterine Doppler indices, and Doppler vascular indices of the endometrium and subendometrium in the periovulatory and midluteal phases were performed with 3DPDUS.

RESULTS

There was a significant increase in the endometrial thickness, endometrial volume, and endometrial and subendometrial vascularity indices (vascularization index, flow index, vascularization flow index) after 6 months of metformin treatment in PCOS women, whereas there was no change in the resistance index and the pulsatility index of the uterine artery in both periovulatory and midluteal phases.

CONCLUSIONS

Metformin, owing to its metabolic, endocrine, vascular, and anti-inflammatory effects, improves markers of endometrial receptivity.

Endometrial spiral artery Doppler parameters in unexplained infertility patients: is endometrial perfusion an important factor in the etiopathogenesis?

OBJECTIVE

Uterine perfusion, particularly the endometrial blood flow, may have an important role in endometrial receptivity. In order to assess the contribution of sub endometrial blood flow in the etiopathogenesis of unexplained infertility mid luteal- peri-implantation period spiral artery transvaginal color Doppler parameters were measured and compared with fertile controls.

MATERIAL AND METHODS

Forty-two consecutive patients admitted to Izmir Katip Celebi University Ataturk Training and Research Hospital, Department of Obstetric and Gynecology with the diagnosis of unexplained infertility after standard diagnostic work up constituted the study group and they were compared with a fertile control group admitted to hospital with non specific gynecological complaints or for check-up in the same period. Mid luteal transvaginal color Doppler ultrasonography was applied to each patient by the same radiologist who was blind to the diagnosis of the particular patient and, RI (resistance index) and PI (pulsatility index) values were calculated.

RESULTS

There were no significant differences between the two groups, in respect to age, body mass index, basal hormonal and mid luteal progesterone levels (p>0.05). For the fertile control group, mid luteal-peri-implantation phase endometrial spiral artery mean RI values were calculated as 0.48±0.08 SD and mean PI values as 0.65±0.18 SD. For the study group, mean RI values were calculated as 0.54±0.07 SD, PI values were calculated as 0.80±0.16 SD. The differences for RI (p=0.009) and PI (p=0.004) were statistically significant.

CONCLUSION

According to Doppler parameters, unexplained infertility patients have high impedance blood flow in spiral arteries which means that peri-implantation blood flow in these patient is lower than fertile controls. These findings suggest that endometrial perfusion may have an important contribution to etiopathogenesis of unexplained infertility.

Effects of physiotherapeutic TENS in a woman with unexplained infertility

Unexplained infertility (UI) is a difficult diagnosis in the field of obstetrics and gynaecology. This report describes TENS treatment as an adjunct therapy for a 30-year-old woman with long-standing UI who was scheduled to undergo ovarian stimulation for in vitro fertilization (IVF) and embryo transfer. She had three unsuccessful intrauterine insemination treatments. Her last IVF treatment also failed. The treatment consisted of burst-TENS for seven sessions, which was applied daily from the second day of induction of ovulation (IO) to hCG administration. The transvaginal ultrasonography with pulsed Doppler curves was performed to measure the uterine artery impedance indices of Pulsatility Index (PI) and Resistance Index (RI). Before TENS application, on the first day of IO, the PI and RI for right side uterine artery were 3.96 and 0.96, respectively. For left uterine artery, the PI and RI were 6.92 and 1, respectively. After treatment with TENS, on the day of hCG administration, the PI and RI for right side uterine artery were 3.39 and 0.90, respectively. On the left side, they were PI=2.62 and RI=0.86. IVF was performed and on the day of oocytes collection, 22 oocytes were collected and inseminated. Fertilization was confirmed 16 hours after insemination by visualization of 2 pronuclei. A singleton pregnancy was achieved by the presence of a fetal sac during an ultrasound examination. It is concluded that the addition of TENS resulted in remarkable reduction of uterine artery PI and RI and a successful pregnancy after IVF for this woman with UI.

Endometrial blood flow is impaired in women with polycystic ovarian syndrome who are clinically hyperandrogenic

OBJECTIVES

To quantify endometrial and subendometrial blood flow in Caucasian women with polycystic ovarian syndrome (PCOS) and to determine whether these values differ according to the phenotypic expression of PCOS.

METHODS

Transvaginal pelvic ultrasound was performed on the 3(rd)-5(th) day of the menstrual cycle in 36 women with PCOS and 36 controls to examine the endometrial and subendometrial vascularity. The subendometrial and endometrial blood flow indices (vascularizaton index (VI), flow index (FI) and vascularization flow index (VFI)) were measured using three-dimensional power Doppler angiography. Uterine artery blood flow was assessed through analysis of two-dimensional (2D) pulsed-wave Doppler waveforms. Analysis was performed to compare PCOS with non-PCOS women, and subgroup analysis was performed of the PCOS women categorized according to their phenotypic manifestation.

RESULTS

There were no significant differences in endometrial volume, subendometrial vascularity and uterine artery blood flow between women with PCOS and controls after controlling for body mass index (BMI). On subgroup analysis, compared with anovulatory but clinically normoandrogenic women with polycystic ovaries (PCO) and with controls, women with PCO who were both clinically hyperandrogenic and anovulatory had significantly lower endometrial (VI: 0.57% vs. 1.11% and 0.86%, respectively, both P = 0.01; VFI: 0.14 vs. 0.42 and 0.28, respectively, both P = 0.02) and subendometrial (VI: 1.59% vs. 3.17% and 2.47%, P = 0.01 and 0.02, respectively; VFI: 0.50 vs. 1.67 and 0.96, P = 0.01 and 0.02, respectively) blood flow. Moreover, clinically hyperandrogenic but ovulatory women with PCO also had significantly lower endometrial blood flow (VI: 0.52% vs. 1.11%, P = 0.04) than did anovulatory but clinically normoandrogenic women with PCO. There were no differences in any of the 2D pulsed-wave Doppler measures of blood flow between the subgroups.

CONCLUSIONS

Subendometrial and endometrial blood flow is significantly impaired in women with PCOS who have clinical signs of hyperandrogenism.

Factors affecting endometrial and subendometrial blood flow measured by three-dimensional power Doppler ultrasound during IVF treatment

BACKGROUND

No information exists in the literature regarding the factors affecting the blood flow towards the endometrial and subendometrial regions during IVF treatment.

METHODS

We examined the effect of women's age, their smoking habits, their type of infertility (i.e. primary or secondary) and parity, causes of infertility and serum estradiol (E2) concentration on endometrial and subendometrial blood flows as measured by a three-dimensional (3D) power Doppler ultrasound during IVF treatment. All patients received a standard long protocol of ovarian stimulation and serum E2 concentration was determined on the day of hCG. 3D ultrasound examination with power Doppler was performed on the day of oocyte collection to determine vascularization index (VI), flow index (FI) and vascularization flow index (VFI) of endometrial and subendometrial regions.

RESULTS

The age of women, their smoking habits, their types of infertility and parity and causes of infertility had no effect on the endometrial and subendometrial 3D power Doppler flow indices. There was a negative correlation between serum E(2) concentration and endometrial FI (r = -0.109; P = 0.006).

CONCLUSIONS

Endometrial blood flow in IVF treatment was negatively affected by serum E2 concentration only.

Present concept of unexplained infertility

Despite improvements in both diagnostic assessment and treatment of infertile couples, many couples still have no explanation for their infertility. Unexplained infertility (the failure to conceive of a couple in whom no definitive cause for infertility can be found) has an incidence of 10-20% in all infertile couples. The incidence varies with the population studied and with the criteria used. Unexplained infertility is not an absolute condition but rather a relative inability to conceive, and many of these couples may conceive without treatment. The treatment options for unexplained infertility are several and the treatment results are promising. Expectant management can be recommended if the woman is under 28-30 years of age and the infertility duration is less than 2-3 years. In vitro fertilization (IVF) has revolutionized the treatment of infertile couples, as well as profoundly increasing the basic understanding of human reproduction. IVF can be used as both a diagnostic and a therapeutic tool in couples with unexplained infertility. The pregnancy rates with IVF are good, at 40% per treatment cycle. In addition, the outcome of pregnancies among women with unexplained infertility is generally comparable to that of spontaneous and other pregnancies using assisted reproductive technologies.