Table 1 Researches of relationship between endometrial features and endometrial receptivity
Research | Research design | Country | Inclusion population | Sample size | Leading indicator | Â |
|---|---|---|---|---|---|---|
Sedigheh Amooee, [87] | Retrospective cross-sectional study | Iran | PCOS infertility patients aged 15–38 years | 70 | endometrial histology, luteinizing hormone, follicle stimulating hormone, thyroid stimulating hormone, testosterone, prolactin, fasting blood glucose, body mass index ( BMI) and duration of infertility | The histological results of women with PCOS showed that proliferative endometrium accounted for 54.3%, proliferative abnormal endometrium accounted for 17.1%, secretory endometrium accounted for 8.6%, endometrial polyps accounted for 17.1%, and these percentages of UI patients were 28.6%, 0%, 54.3%, and 20%, respectively |
Li Wang, 2019 [103] | randomized controlled trial | China | Patients diagnosed with PCOS | 160 | endometrial thickness, morphology, uterine artery blood flow, subendometrial blood flow, endometrial volume and vascularization index, biochemical pregnancy rate, clinical pregnancy rate, persistent pregnancy rate | After PCOS patients use of letrozole, their endometrial thickness had increased and the morphology was most of type A, which improves endometrial receptivity and improves pregnancy rates |
Manal T Al-Obaidi, 2019 [3] | Random blind-free control experiment | Iraq | Infertile PCOS patients | 80 | Follicle growth on day 12–13, endometrial thickness, Uterine artery resistance index, pulsatility index, contraction / diastolic velocity ratio | Compared with the clomiphene citrate group, the endometrial thickness was significantly higher in the cozole group. The resistance index and pulsatility index of the patients in the cozole group and pregnant women were lower than those in the non-pregnant group |
Shaoquan Shi, [93] | case control study | China | PCOS patients resistant to clomiphene citrate | 96 | Number of growing and mature follicles, serum estrogen, progesterone, endometrial thickness, pregnancy rate, abortion rate | There was no significant difference in the number of mature follicle cycles between HMG group and letrozole group, clinical pregnancy rate and abortion rate. There was no significant difference in endometrial thickness between the two groups on the day of HCG injection; Serum estradiol ( E2) was lower in letrozole group. The incidence of ovarian cysts was lower than HMG group. The incidence of ovarian hyperstimulation syndrome in letrozole group was lower than that in HMG group |
Taosa, [96] | case control study | China | PCOS infertility patients with normal uterus and ovary morphology | 162 | Vaginal ultrasound parameters, endometrial thickness and volume, Uterine artery resistance index, pulsatility index, contraction / diastolic velocity ratio | When endometrial thickness ≤ 7.0 mm, endometrial volume ≤ 2 mL, uterine spiral artery PI ≥ 1.6, RI ≥ 0.72 and S/D ≥ 3.6, PCOS patients have an increased risk of poor endometrial receptivity |
Maryam Eftekhar, 2018 [19] | randomized controlled trial | Iran | Patients with poor endometrial receptivity receiving embryo transfer | 83 | endometrial thickness, chemical pregnancy rates, clinical and ongoing pregnancy rates | Increasing endometrial thickness within a certain range, especially when endometrial thickness is ≥ 7 mm, can significantly increase the implantation rate and cycle pregnancy rate in patients undergoing frozen embryo transfer |