The use of real time strain endometrial elastosonography plus endometrial thickness and vascularization flow index to predict endometrial receptivity in IVF treatments: a pilot study

BACKGROUND

The usefulness of endometrium strain elastosonography (SE) for the evaluation of endometrial receptivity in women undergoing in vitro fertilization (IVF) remains controversial. The objective of this prospective, observational study was to evaluate the correlation between endometrial thickness (EMT) and its related strain (ESR) on the day of ovulation triggering (hCG-d) and in vitro fertilization outcomes. Additionally, 3D Power Doppler vascular indices (3DPDVI) were also analysed.

METHODS

We included all the patients undergoing fresh IVF-single blastocyst transfer cycle from January 2021 to August 2021 at our center. On hCG-d, after B-mode scanning was completed to measure the EMT, the mode was changed to elastosonography to evaluate the ESR (ratio between endometrial tissue and the myometrium below). At the end of examination, the Endometrial Volume (EV) and 3DPDVI (vascularization index [VI], flow index [FI] and vascularization flow index [VFI]), were assessed. Statistical analysis was completed using STATA MP16 software.

RESULTS

A total number of 57 women were included. Based on the EMT on hCG-d, women were divided into two groups, Group 1: <7 mm and Group 2 ≥ 7 mm. Women with EMT < 7 mm had a significantly higher ESR (p = 0.004) and lower pregnancy rate (p = 0.04). Additionally, low ESR values were correlated with high VFI values (rho = -0.8; 95% CI = -0.9- -0.6; p < 0.0001) and EMT ≥ 7 mm could be predicted by low ESR (OR = 0.01; 95% CI = 0.01-0.30; p = 0.008, area under the ROC curve: 0.70). After all, in multiple logistic regression analysis, low values of ESR (p = 0.050) and high values of EMT (p = 0.051) on hCG-d had borderline statistical effects on pregnancy rate.

CONCLUSIONS

The ESR may be useful to improve the ultrasound evaluation of the endometrial quality in infertile women candidates to IVF/ICS. Given the small sample size of our study, the usefulness of strain elastosonography in this patients, needs further investigation.

Perifollicular blood flow and its relationship with endometrial vascularity, follicular fluid EG-VEGF, IGF-1, and inhibin-a levels and IVF outcomes

PURPOSE

The aim of this study is to investigate the association of perifollicular blood flow (PFBF) with follicular fluid EG-VEGF, inhibin-a, and insulin-like growth factor-1 (IGF-1) concentrations, endometrial vascularity, and IVF outcomes.

METHODS

Forty women with tubal factor infertility were included in a prospective cohort study. Each woman underwent IVF/ICSI procedure. Individual follicles of ≥16 mm (n = 156) were evaluated by power Doppler analysis and categorized as well-vascularized follicles (WVFs) or poorly vascularized follicles (PVFs). WVFs referred to those with perifollicular vascularity of 51-100 %. Each follicular fluid (FF) was individually aspirated and FF/serum EG-VEGF, inhibin-a, and FF IGF-1 levels were evaluated. Zones III-IV endometrial vascularity was classified as a well-vascularized endometrium (WVE). The presence of a WVE and mature oocytes, in addition to the embryo quality and clinical pregnancy rate (CPR), were recorded for each follicle. The main outcome measures were FF serum EG-VEGF, inhibin-a, IGF-1 levels, and WVE and IVF outcome per PFBF.

RESULTS

For WVFs, the level of FF EG-VEGF (p = 0.008), oocyte quality (p = 0.001), embryo quality (p = 0.002), a WVE (p = 0.001), and CPR (p = 0.04) increased significantly. The pregnant group was characterized by increased numbers of WVFs (p = 0.044), a WVE (p = 0.022), and increased levels of FF IGF-1 (p = 0.001) and serum EG-VEGF (p = 0.03). FF IGF-1 >50 ng/mL (AUC 0.72) had 75 % sensitivity and 64 % specificity for predicting CPR.

CONCLUSIONS

WVFs yield high-quality oocytes and embryos, a WVE, increased FF EG-VEGF levels, and increased CPRs.