The usefulness of endometrial thickness, morphology and vasculature by 2D Doppler ultrasound in prediction of pregnancy in IVF/ICSI cycles

Comparative study of endometrial & subendometrial angiogenesis in unexplained infertile versus normal fertile women

Background & objectives:

Local angiogenesis in endometrium has been shown to be an essential pre-requisite for endometrial receptivity needed for implantation and gestation. Recently, numerous diagnostic gears have been projected to ‘measure’ or ‘estimate’ the endometrial receptivity relying upon angiogenic factors helping throughout implantation. This study evaluated the endometrial and subendometrial blood flow and the local endometrial gland vascular endothelial growth factor (EG-VEGF) expression as markers of local angiogenesis.

Methods:

The present study was done to give quantitative assessment of endometrial thickness (ET), endometrial blood flow and subendometrial blood flow colour Doppler indices with endometrial vascular zones. Endometrial biopsy was taken and with VEGF stained and scored with immunohistochemistry.

Results:

The mean ET for fertile women was 9.41 mm, while in unexplained infertile women it was around 7.90 mm. Upon comparison of ET with EG-VEGF which is considered as a gold standard with correlation coefficient, the present study suggested a positive correlation of EG-VEGF with ET, endometrial pulsatility index (PI), and subendometrial PI also the vascular zones were considered as significant. However, a strong negative correlation was seen with subendometrial resistivity index and PI.

Interpretation & conclusions:

The present study suggests that uterine ultrasound, uterine colour Doppler and EG-VEGF are parameters which can be used as markers of local angiogenesis for endometrial receptivity in the evaluation of women with unexplained infertility.

Conventional and modern markers of endometrial receptivity: a systematic review and meta-analysis

BACKGROUND

Early reproductive failure is the most common complication of pregnancy with only 30% of conceptions reaching live birth. Establishing a successful pregnancy depends upon implantation, a complex process involving interactions between the endometrium and the blastocyst. It is estimated that embryos account for one-third of implantation failures, while suboptimal endometrial receptivity and altered embryo-endometrial dialogue are responsible for the remaining two-thirds. Endometrial receptivity has been the focus of extensive research for over 80 years, leading to an indepth understanding of the processes associated with embryo-endometrial cross-talk and implantation. However, little progress has been achieved to translate this understanding into clinically meaningful prognostic tests and treatments for suboptimal endometrial receptivity.

OBJECTIVE AND RATIONALE

The objective of this systematic review was to examine the evidence from observational studies supporting the use of endometrial receptivity markers as prognostic factors for pregnancy outcome in women wishing to conceive, in order to aid clinicians in choosing the most useful marker in clinical practice and for informing further research.

SEARCH METHODS

The review protocol was registered with PROSPERO (CRD42017077891). MEDLINE and Embase were searched for observational studies published from inception until 26 February 2018. We included studies that measured potential markers of endometrial receptivity prior to pregnancy attempts and reported the subsequent pregnancy outcomes. We performed association and accuracy analyses using clinical pregnancy as an outcome to reflect the presence of receptive endometrium. The Newcastle-Ottawa scale for observational studies was employed to assess the quality of the included studies.

OUTCOMES

We included 163 studies (88 834 women) of moderate overall quality in the narrative synthesis, out of which 96 were included in the meta-analyses. Studies reported on various endometrial receptivity markers evaluated by ultrasound, endometrial biopsy, endometrial fluid aspirate and hysteroscopy in the context of natural conception, IUI and IVF. Associations were identified between clinical pregnancy and various endometrial receptivity markers (endometrial thickness, endometrial pattern, Doppler indices, endometrial wave-like activity and various molecules); however, their poor ability to predict clinical pregnancy prevents them from being used in clinical practice. Results from several modern molecular tests are promising and further data are awaited.

WIDER IMPLICATIONS

The post-test probabilities from our analyses may be used in clinical practice to manage couples' expectations during fertility treatments (IUI and IVF). Conventionally, endometrial receptivity is seen as a dichotomous outcome (present or absent), but we propose that various levels of endometrial receptivity exist within the window of implantation. For instance, different transcriptomic signatures could represent varying levels of endometrial receptivity, which can be linked to different pregnancy outcomes. Many studies reported the means of a particular biomarker in those who achieved a pregnancy compared with those who did not. However, extreme values of a biomarker (as opposite to the means) may have significant prognostic and diagnostic implications that are not captured in the means. Therefore, we suggest reporting the outcomes by categories of biomarker levels rather than reporting means of biomarker levels within clinical outcome groups.

The correlation between endometrial thickness and pregnancy outcomes in fresh ART cycles with different age groups: a retrospective study

Background

In assisted reproductive technology (ART) cycles in addition to embryo quality, the receptivity of the endometrium plays the main role in clinical outcomes. Endometrial receptivity is necessary to implantation of an embryo, and ultrasound has been established as an appreciated, simple, and non-invasive technique in the evaluation of the endometrial preparation before embryo transfer in fresh in vitro fertilization (IVF) cycles. Debate on the predictive value measuring endometrial thickness before administering human chorionic gonadotropin (HCG) for ovulation triggering in ART is ongoing. In order to explore the impact of endometrial thickness on triggering day on ongoing pregnancy rate (OPR) in ART cycles, we retrospectively analyzed data from 1000 patients undergoing IVF/ICSI cycles.

Results

The data showed pregnancy rate was increased in the endometrial thickness of 8 mm to 11 mm then decreased, and in endometrial thickness (Ent) > 14 mm, pregnancy rate was zero. There were significant differences in endometrial thickness and pregnancy outcomes between different age groups. The pregnancy rate was higher (32%) in 23–30 years old women, and the range of Ent in this group was 6–12 mm. Also, the data showed a positive correlation between Ent with AMH and estradiol levels and the number of COC and MII oocytes and a negative correlation between female age with Ent.

Conclusion

The result showed that Ent on hCG administration day is associated with pregnancy outcomes in fresh IVF/ICSI cycles with different age groups, although some of the clinical parameters may have an effect on Ent. Large studies are needed to make a definitive conclusion.

Predictive factors for biochemical pregnancy in intracytoplasmic sperm injection cycles

The aim of this study was to investigate which factors contribute to the incidence of biochemical pregnancy (BP) in intracytoplasmic sperm injection (ICSI) cycles. This cohort study included cycles performed from June 2010 to September 2016 in a private, university-affiliated IVF centre. Cycles were split into four groups, depending on the pregnancy outcomes: Clinical Pregnancy (CP, n = 903), Biochemical Pregnancy (BP, n = 55), Miscarriage (MI, n = 142) and Negative Pregnancy (NP, n = 2034). The effects of ovarian stimulation, laboratory data and seminal parameters on pregnancy outcomes were evaluated using adjusted general linear models. Discriminant analyses were conducted to construct a model for pregnancy prediction and to establish cut-offs for BP. The total sperm count (p = 0.035), total and progressive sperm motility (p = 0.001 and p = 0.023, respectively), total motile sperm count (TMSC, p = 0.029) and the endometrial thickness (p < 0.001) were lower among BP group cycles. Lower rates of high-quality cleavage-stage embryos were observed in the BP group compared to CP and MI groups (p < 0.001). In discriminant analyses, cut-offs for BP prediction were established for the following factors: endometrial thickness < 11 mm, sperm motility < 55.5% and total dose of follicle-stimulating hormone (FSH)> 2400 IU. The incidence of biochemical pregnancy was four times higher when the aforementioned factors did not meet the defined cut-offs. The combination of suboptimal endometrial development and poor seminal and embryo quality contribute to an increased incidence of biochemical pregnancy in ICSI cycles.