Sperm selection by zona adhesion improves assisted reproductive treatment outcomes.

BACKGROUND: Zona pellucida is one of the main selective barriers for the spermatozoa before reaching the oocyte. Using native zona in the sperm selection prior to Intracytoplasmic Sperm Injection (ICSI) has been proven effective but inconvenient approach in In Vitro Fertilisation (IVF) laboratory. The application of autologous solubilised zonae pellucidae in the sperm selection prior to ICSI has not been studied yet. OBJECTIVES: To compare the assisted reproductive treatment (ART) outcomes (implantation, pregnancy, live birth, and miscarriage rates) after ICSI performed with spermatozoa selected on their ability to adhere to immobilised solubilised zonae pellucidae and conventionally selected spermatozoa. MATERIALS AND METHODS: In total, 500 couples fulfilled the inclusion criteria and 368 of them were included in the study. After random allocation, 192 couples had spermatozoa selected by sperm-zona adhesion for ICSI (study group) and 176 patients underwent standard ICSI (control group). In the study group, patients' own zonae were acid solubilised and immobilised on petri dishes. The partner's motile spermatozoa were placed in the dishes and the adhered spermatozoa were used for ICSI. For the control group, the conventional sperm selection by morphological criteria was applied prior ICSI. All women underwent frozen ET with euploid embryos. Chi square test was used to compare the data. RESULTS: The sperm selection by zona adhesion resulted in significantly higher implantation rate (50.4% vs. 37.0%, p = 0.003), clinical pregnancy rate (43.8% vs. 33.3%, p = 0.018) and live birth rate (38.0% vs. 25.9%, p = 0.004) and significantly lower incidence of miscarriage (11.3% vs. 22.2%, p = 0.044) in comparison to the conventional method of the sperm selection. DISCUSSION AND CONCLUSION: The application of solubilised zonae pellucidae in the sperm selection for ICSI benefits ART outcomes in couples with unexplained infertility. Moreover, sperm-zona selection significantly reduces the risk of miscarriages.

NOTCH1- and CD117-positive stem cells in human endometrium and their implications for successful implantation.

OBJECTIVE: To investigate the quantity of 2 stem cell types in the endometrial stroma of women undergoing in vitro fertilization and their association with steroid hormone signaling and implantation success after embryo transfer. DESIGN: Prospective cohort study. SETTING: Private hospital. PATIENT(S): A total of 109 patients undergoing in vitro fertilization. INTERVENTION(S): Not applicable. MAIN OUTCOME MEASURE(S): Immunohistochemistry staining of endometrial biopsies taken during the midluteal phase using antibodies against NOTCH1 and CD117 was performed. The percentage of endometrial stromal cells positive for these markers was determined. The link of these stem cell percentages with the serum progesterone and estradiol levels and the endometrial expression of their respective receptors were assessed. After embryo transfer, the quantity of stained cells for each marker was also compared according to implantation outcome. RESULT(S): The percentage of NOTCH1+ stromal cells ranged from 0.003%-2.112% (median, 0.062%) and was significantly higher than that of CD117+ cells, which ranged from 0.000%-0.210% (median, 0.020%) (Z = -7.035). The percentage of NOTCH1+ stem cells showed no difference between the studied serum hormone level groups and no relationship with the expression of their receptors in the endometrium. In contrast, the number of CD117+ cells significantly differed between patients with high and low levels of serum progesterone (cutoff, 14.9 ng/mL) and estradiol (cutoff, 135.6 pg/mL). Furthermore, the quantity of CD117+ stem cells was positively correlated with the progesterone receptor (R = 0.277) and estradiol receptor (R= 0.318) expression levels in the endometrium. Although the quantity of NOTCH1+ cells did not differ between the 2 implantation groups, the median percentage of CD117+ cells was significantly higher in patients with successful implantation than in those with unsuccessful implantation (0.03% vs. 0.01%, respectively). The cutoff value for the percentage of CD117+ cells predicting successful implantation was 0.018% (area under the curve, 0.66; 95% confidence interval, 0.56-0.77; sensitivity, 63.1%; specificity, 61.4%). CONCLUSION(S): This study indicates that the quantity of certain stem cell types (CD117+), but not others (NOTCH1+), in the functional endometrium is associated with implantation success and sex hormone signaling during the midluteal phase. These findings highlight the role of CD117+ cells in preparing the endometrium for embryo implantation, and their quantity may be an indirect indicator of endometrial receptivity.

Endometrial immune cell ratios and implantation success in patients with recurrent implantation failure.

The objective of this study was to compare the endometrial immune cells quantities and ratios during the mid-luteal phase between women with recurrent implantation failure (RIF) with successful and unsuccessful embryo implantation. For this purpose, endometrial biopsies from 116 women aged between 29 and 46 with history of RIF undergoing Assisted Reproductive Technology (ART) without endometrial pathologies were immunohistochemically stained for CD3 + T-cells, CD4 + T-helpers, CD8 + T-killers, CD14 + monocytes, CD68 + macrophages, CD56 + NK cells and CD79α+ B-cells. Endometrial immune cells quantities and ratios were compared based on the embryo implantation outcome in the subsequent embryo transfer cycle. Spearman correlation analysis and Mann-Whitney U test were used to analyse the obtained data. Patients who experienced successful implantation at the subsequent cycle had significantly lower percentage of CD3 + T cells, and higher ratios of CD4 + /CD8 + , CD4 + /CD3 + and CD68 + /CD3 + than the patients who experienced another failure in implantation. In addition, the ratios of CD3 + /CD14 + , CD79α+ /CD14 + and CD56 + /CD14 + were significantly lower in the successful implantation group than that in the unsuccessful one. A cut off value of CD68 + /CD3 + ratio higher than 0.85 (AUC 0.67, 95% CI 0.56-0.79), CD4 + /CD3 + ratio higher than 0.19 (AUC 0.67, 95% CI 0.56-0.79) and CD4 + /CD8 + ratio higher than 0.43 (AUC 0.62, 95% CI 0.50-0.73) could be predictive factors for successful implantation in RIF patients. Knowledge on the immune cell composition could assist in the evaluation of the endometrial receptivity in RIF patients.

Vertical Transmission of SARS-CoV-2 Infection and Miscarriage in the Second Trimester: Report of an Immunohistochemically Proven Case.

It is an acknowledged fact that SARS-CoV-2 exhibits tropism for the human placenta. A possible mechanism of SARS-CoV-2 entry into host cells is via angiotensin-converting enzyme 2 (ACE2) receptors, which are expressed in trophoblasts, endothelial cells, and macrophages. The present study describes a case of spontaneous miscarriage in the 20th gestational week after maternal SARS-CoV-2 infection. The placenta and various fetal organs were examined for structural alterations and expression of the viral nucleocapsid protein and several immune cell markers via immunohistochemistry (IHC). Histopathological examination of the placenta revealed acute chorioamnionitis, acute subamnionic placentitis, multiple intervillous thrombi, increased fibrinoid deposition, and necrotic changes of the chorionic villi. Immunohistochemistry confirmed the presence of SARS-CoV-2 nucleocapsid protein regions predominantly in the syncytiotrophoblast. Staining of the placental tissue for different markers helped elucidate the distribution of immune cells. Pathomorphological examination of the fetal organs demonstrated changes in microcirculation with the presence of sludge phenomenon and diapedesis haemorrhages, mostly in the lungs, brain, and myocardium. IHC staining of fetal organs revealed expression of SARS-CoV-2 nucleocapsid protein, which was detected to the highest extent in the brain, lungs, and liver. The findings of the present report support the hypothesis of possible vertical transmission of SARS-CoV-2 from mother to fetus.

Decreased number of p16-positive senescent cells in human endometrium as a marker of miscarriage.

PURPOSE: The aim of this study was to evaluate whether the number of p16-positive cells in the functional layer of the endometrium could be a useful biomarker to identify women with recurrent implantation failure (RIF) undergoing in vitro fertilization (IVF) at risk of miscarriage. METHODS: Immunohistochemical staining was performed in 311 endometrial biopsies taken during mid-luteal phase using antibody against p16INK4A. The percentage of p16-positive cells was determined in luminal, glandular and stromal endometrial cells. After embryo transfer, women were divided into the following groups: unsuccessful embryo implantation (n = 151), miscarriage (n = 66) and live birth (n = 94). The percentage of p16-positive cells in all endometrial compartments was compared among these groups. RESULTS: We found that the percentages of p16-positive glandular and luminal epithelial endometrial cells were significantly higher in patients with live births compared to women with miscarriage (9.3% vs. 2.9%, P < 0.001; and 35.2% vs. 11.7%, P = 0.001, respectively). This tendency was not confirmed in thе stroma. The cut-off values with p16-positive luminal cells lower than 12.5% and p16-positive glandular cells lower than 3.2% could be predictive factors for miscarriage (AUC 0.80 and 0.79; sensitivity 71.3% and 74.5%; specificity 74.2% and 71.2%, respectively). CONCLUSION: A decreased number of senescent p16-positive cells could be involved in the implantation failures and aetiology of recurrent miscarriage. Women with history of RIF with reduced populations of p16-positive cells in the endometrial glandular and luminal epithelium may be at greater risk for unsuccessful implantation and miscarriage. The percentage of p16-positive luminal epithelial cells may be clinically useful as a biomarker of miscarriage.