Oocyte matched follicular fluid anti-Müllerian hormone is an excellent predictor of live birth after fresh single embryo transfer

Anti-Müllerian hormone: biology and role in endocrinology and cancers

Anti-Müllerian hormone (AMH) is a peptide belonging to the transforming growth factor beta superfamily and acts exclusively through its receptor type 2 (AMHR2). From the 8th week of pregnancy, AMH is produced by Sertoli cells, and from the 23rd week of gestation, it is produced by granulosa cells of the ovary. AMH plays a critical role in regulating gonadotropin secretion, ovarian tissue responsiveness to pituitary hormones, and the pathogenesis of polycystic ovarian syndrome. It inhibits the transition from primordial to primary follicles and is considered the best marker of ovarian reserve. Therefore, measuring AMH concentration of the hormone is valuable in managing assisted reproductive technologies. AMH was initially discovered through its role in the degeneration of Müllerian ducts in male fetuses. However, due to its ability to inhibit the cell cycle and induce apoptosis, it has also garnered interest in oncology. For example, antibodies targeting AMHR2 are being investigated for their potential in diagnosing and treating various cancers. Additionally, AMH is present in motor neurons and functions as a protective and growth factor. Consequently, it is involved in learning and memory processes and may support the treatment of Alzheimer's disease. This review aims to provide a comprehensive overview of the biology of AMH and its role in both endocrinology and oncology.

Basal FSH values are positively associated with aneuploidy incidence in pre-advanced maternal age (AMA) but not in AMA patients

PURPOSE

To assess the impact of maternal age on the association between maternal basal FSH and aneuploidy.

METHODS

A retrospective study including data from 1749 blastocysts diagnosed as euploid or aneuploid by PGT-A (preimplantation genetic testing for aneuploidy). Aneuploidy incidence was compared between embryos from mothers with high vs. low basal FSH levels (above and below the group median, respectively) in total, pre-AMA (advanced maternal age; < 35 years, 198 embryos) and AMA (≥ 35 years, 1551 embryos) patient groups, separately. To control for the interference of potentially confounding variables, the association between aneuploidy and high basal FSH levels was assessed by multivariate logistic analysis in overall, pre-AMA and AMA patient groups.

RESULTS

Overall, aneuploidy rate was 9% higher (p = 0.02) in embryos from patients with high basal FSH (63.7%) compared to those with low basal FSH (58.4%). In the pre-AMA subgroup, aneuploidy incidence was 35% higher (p = 0.04) in embryos from patients with high basal FSH (53.5%) compared to those with low basal FSH (39.4%). Differently, aneuploidy occurrence did not vary between embryos from AMA patients with low (61.0%) and high (64.8%) basal FSH (p = 0.12). The multivariate analysis revealed that, in pre-AMA embryos, the association between aneuploidy occurrence and high basal FSH is independent of potential confounding variables (p = 0.04).

CONCLUSION

Maternal basal FSH values are associated with embryo aneuploidy in pre-AMA but not in AMA patients. The present findings suggest that basal FSH is a useful parameter to assess aneuploidy risk in pre-AMA patients and reinforce the hypothesis that excessive FSH signalling can predispose to oocyte meiotic errors.

The association between female age and pregnancy outcomes in patients receiving first elective single embryo transfer cycle: a retrospective cohort study

This study aimed to explore the relationship between female age and pregnancy outcomes in patients undergoing their first elective single embryo transfer (eSET) of in vitro fertilization (IVF) cycles. The retrospective cohort study encompassed 7089 IVF/intracytoplasmic sperm injection (ICSI) patients of the Reproductive Medicine Center, Henan Provincial Peoples' Hospital of China, from September 1, 2016, to May 31, 2022. Patients all received the first eSET in their IVF/ICSI cycles. A generalized additive model (GAM) was employed to examine the the dose-response correlation between age and pregnancy outcomes, namely the clinical pregnancy rate (CPR) and ongoing pregnancy rate (OPR). Logistic regression model was employed to ascertain the correlation between the CPR/OPR and age. The study cohort has an average age of 30.74; 3843 patients got clinical pregnancy rate of 61.40% and ongoing pregnancy rate of 54.21%. The multiple pregnancy rate of is 1.24%. For patients aged 34 and above, the CPR decreased by 10% for every 1-year increase in age (adjusted OR 0.90, 95% CI 0.84-0.96, p < 0.0001). Similarly, the OPR decreased by 16% for every 1-year increase in age (adjusted OR 0.84, 95% CI 0.81-0.88, p < 0.0001). Patients aged 35-37 years had an acceptable OPR of 52.4% after eSET, with a low multiple pregnancy rate (1.1%). Pregnancy outcomes were significantly better in blastocyst cycles compared to cleavage embryo cycles, and this trend was more pronounced in older patients. There was a non-linear relationship between female age and pregnancy outcomes in patients undergoing their first eSET cycles. The clinical pregnancy rate and ongoing pregnancy rate decreased significantly with age, especially in women older than 34 years. For patients under 37 years old, single embryo transfer should be prioritized. For patients over 38 years old with available blastocysts, eSET is also recommended.

Antimüllerian hormone levels and IVF outcomes in polycystic ovary syndrome women: a scoping review

Antimüllerian hormone (AMH) is a homodimeric glycoprotein secreted by granulosa cells from primary to large antral follicles, and it plays an important role in the regulation of early follicle growth. It is considered a reliable marker of ovarian reserve and a predictor of ovarian response to controlled stimulation. Polycystic ovary syndrome (PCOS) is an endocrine condition that affects women of reproductive age worldwide, and it is associated with high levels of AMH. PCOS patients may have worse maturation and fertilization rates compared to normo-ovulatory women. Some studies have demonstrated a positive correlation between AMH levels and qualitative aspects of assisted reproduction treatment; but it is not clear whether high levels of both serum and follicular fluid AMH in PCOS patients correlate with in vitro fertilization outcomes. We ran this scoping review of the literature to address this specific question. We comprehensively searched the databases PubMed and Cochrane Library until January 2023. We found that higher AMH levels are associated with higher oocyte yield, but PCOS patients tend to have fewer mature oocytes and impaired embryo quality and implantation rates. Pregnancy rates, however, are not affected by AMH levels or laboratorial outcomes. We also found that higher AMH levels are associated with worse PCOS features.

Is elevated baseline SHBG associated with increased ovulation?

Sexual hormone binding globulin (SHBG) is associated with the endocrine and reproductive systems. We aimed to investigate the role of SHBG in the reproductive process. Therefore, we conducted a secondary analysis of the PCOSAct (Polycystic Ovary Syndrome and Acupuncture Clinical Trial) study, which involved 21 sites in China and a total of 1000 women with PCOS. Out of these, 954 women with SHBG were included in the analysis. Through multivariate analysis of ovulation predictors, we found that age, BMI, estradiol, testosterone, and SHBG all showed a positive predictive value for ovulation (p = 0.0211, 0.0011, 0.0211, 0.0029, 0.0434, respectively). However, the LH to FSH ratio had a negative predictive value (p = 0.0539). Higher quartiles of SHBG were associated with a higher rate of ovulation, and per quartile increased was statistically significant (HR = 1.138, 95%CI [1.054,1.229]). The association remained significant even after adjusting for testosterone (HR = 1.263, 95%CI [1.059, 1.507]). On the other hand, quartiles of testosterone and estradiol did not exhibit any significant tendency toward ovulation. SHBG demonstrated predictive ability for ovulation, conception, pregnancy, and live birth (p < 0.05), and this correlation remained significant after adjusting intervention. Kaplan-Meier curves illustrated that increased levels of SHBG were a factor in high rates of ovulation, conception, and pregnancy. In comparison to other sexual hormones, a higher baseline level of SHBG was related to increased ovulation.

The impact of oocyte central granularity on ICSI practice: developmental competence of dysmorphic and morphologically normal companion oocytes

PURPOSE

To assess the effects of oocyte central granularity and its underlying endocrine environment on developmental competence of dysmorphic and morphologically normal oocytes.

METHODS

Retrospective cohort study including 1,082 patients undergoing autologous ICSI cycles. Of these, 211 patients provided 602 oocytes with central granularity (CG) and 427 morphologically normal cycle companion oocytes (NCG). The remaining 871 patients provided only morphologically normal oocytes in cycles not yielding dysmorphic oocytes (N). Patient profile associated with CG was characterized, and fertilization rates, early morphokinetics and live birth rates were compared between N, CG and NCG groups. Patient characteristics associated with implantation and delivery performance of CG-derived embryos were assessed.

RESULTS

CG was associated with higher maternal age, basal FSH concentrations and total FSH dose, but with lower circulating AMH (p ≤ 0.035). Fertilization rates were reduced and early morphokinetic parameters were delayed in CG (p < 0.025) and NCG (p < 0.05) groups as compared to the N group. Embryos derived from CG oocytes achieved a markedly lower live birth rate (14.9%) as compared to those derived from NCG (36.8%; p = 0.03) and N oocytes (29.8%; p = 0.002). The negative relationship between CG and live birth was confirmed by a multivariate analysis controlling for potential confounders (OR:2.59, IC:1.27-5.31; P = 0.009). Implantation and delivery rates following transfers of CG-derived embryos were inversely associated with maternal age.

CONCLUSION

CG oocytes, but not their morphologically normal cycle companions, have severely compromised developmental competence. Maternal age should be a key parameter in deciding whether or not to utilize CG oocytes in ICSI cycles.

Oocyte secreted factors control genes regulating FSH signaling and the maturation cascade in cumulus cells: the oocyte is not in a hurry

PURPOSE

To assess the effects of the oocyte on mRNA abundance of FSHR, AMH and major genes of the maturation cascade (AREG, EREG, ADAM17, EGFR, PTGS2, TNFAIP6, PTX3, and HAS2) in bovine cumulus cells.

METHODS

(1) Intact cumulus-oocyte complexes, (2) microsurgically oocytectomized cumulus-oolema complexes (OOX), and (3) OOX + denuded oocytes (OOX+DO) were subjected to in vitro maturation (IVM) stimulated with FSH for 22 h or with AREG for 4 and 22 h. After IVM, cumulus cells were separated and relative mRNA abundance was measured by RT-qPCR.

RESULTS

After 22 h of FSH-stimulated IVM, oocytectomy increased FSHR mRNA levels (p=0.005) while decreasing those of AMH (p=0.0004). In parallel, oocytectomy increased mRNA abundance of AREG, EREG, ADAM17, PTGS2, TNFAIP6, and PTX3, while decreasing that of HAS2 (p<0.02). All these effects were abrogated in OOX+DO. Oocytectomy also reduced EGFR mRNA levels (p=0.009), which was not reverted in OOX+DO. The stimulatory effect of oocytectomy on AREG mRNA abundance (p=0.01) and its neutralization in OOX+DO was again observed after 4 h of AREG-stimulated IVM. After 22 h of AREG-stimulated IVM, oocytectomy and addition of DOs to OOX caused the same effects on gene expression observed after 22 h of FSH-stimulated IVM, except for ADAM17 (p<0.025).

CONCLUSION

These findings suggest that oocyte-secreted factors inhibit FSH signaling and the expression of major genes of the maturation cascade in cumulus cells. These may be important actions of the oocyte favoring its communication with cumulus cells and preventing premature activation of the maturation cascade.

Antimüllerian hormone (AMH) and age as predictors of preimplantation genetic testing for aneuploidies (PGT-A) cycle outcomes and blastocyst quality on day 5 in women undergoing in vitro fertilization (IVF)

PURPOSE

The objective of this study was to investigate whether women with diminished ovarian reserve who planned for PGT-A exhibit a lower number of blastocysts for biopsy, ploidy outcomes, and blastocyst quality on day 5, regardless of age.

METHODS

A retrospective analysis was performed between March 2017 and July 2020 at ART Fertility Clinics Abu Dhabi, including couples that were triggered for final oocyte maturation in an ovarian stimulated cycle planned for PGT-A. Patients were stratified into four AMH groups: < 0.65 ng/ml, 0.65-1.29 ng/ml, 1.3-6.25 ng/ml, and > 6.25 ng/ml; four age categories: ≤ 30, 31-35, 36-40, and > 40 years.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 1410 couples with a mean maternal age of 35.2 ± 6.4 years and AMH of 2.7 ± 2.6 ng/ml were included. In a multivariate logistic regression analysis, controlling for age, the chance of having at least one blastocyst biopsied/stimulated cycle (1156/1410), the chance of having at least one euploid blastocyst/stimulated cycle (880/1410), and the chance of having one euploid blastocyst once biopsy was performed (880/1156) were affected in all patients with AMH < 0.65 ng/ml [AdjOR 0.18[0.11-0.31] p = 0.008)], [AdjOR 0.18 [0.11-0.29] p < 0.001], and [AdjOR 0.34 [0.19-0.61] p = 0.015] as well as in patients with AMH 0.65-1.29 ng/ml (AdjOR 0.52 [0.32-0.84] p < 0.001), (AdjOR 0.49 [0.33-0.72] p < 0.001), and (AdjOR 0.57 [0.36-0.90] p < 0.001), respectively. In a multivariate linear regression analysis, AMH values did not affect blastocyst quality (- 0.72 [- 1.03 to - 0.41] p < 0.001).

CONCLUSION

Irrespective of age, patients with diminished ovarian reserve (AMH < 1.3 ng/ml) have a lower chance of having at least one blastocyst biopsied and lower chance of having at least one euploid blastocyst per ovarian stimulated cycle. Blastocyst quality was not affected by AMH values.

Impact of follicular size categories on oocyte quality at trigger day in young and advanced-age patients undergoing GnRH-ant therapy

Aim

To study the effect of follicle sizes of different proportions on oocyte and embryo quality in young and advanced-age patients, and provide evidence for personalized protocol adjustment.

Methods

This was a retrospective real-world data study including a total of 11,462 patients who had started their first in vitro fertilization cycle with a gonadotropin-releasing hormone antagonist (GnRH-ant) protocol during 2018-2021. We classified patients into groups according to the size of the dominant proportion of follicles on the human chorionic gonadotropin (hCG) trigger day: Large, Medium, Small, and Equal (containing equivalent proportions of all three size categories). The Cochran-Mantel-Haenszel test by different Anti-Mullerian Hormone (AMH) and antral follicle count (AFC) was used to compare factors such as the metaphase II (MII) oocyte rate, normal fertilization rate, and two pronuclei (2PN) cleavage rate between groups. General linear model (GLM) analysis was performed for inter-group comparison of the oocyte and embryo quality.

Results

In patients aged < 35 years and with AMH ≥ 1.2μg/L, the MII oocyte percentages in the Large and Medium groups were significantly higher than in the Small group (P < 0.001). The germinal vesicle (GV) oocyte and unavailable oocyte percentages in the Large and Medium groups were lower than in the Small group (P < 0.001). Among patients aged ≥ 35 years with AFC < 5 and AMH ≥ 1.2μg/L, the GV oocyte percentage in the Large group was significantly lower than in the Medium group (2.54% vs. 4.46%, P < 0.001). In patients < 35 years, the GLM demonstrated that the Large and Medium groups had positively impacted on the development of MII oocyte and live birth rate(LBR) of first embryo transfer(ET)(β>0, all P value < 0.05);and had less likely to develop into unavailable oocyte, degenerated oocyte, GV oocyte and MI oocyte rates relative to the Small group(β<0, all P value < 0.05). And among patients ≥ 35 years, the Medium group had positively impacted on the development of MII oocyte and 2PN rates relative to the Small group(β>0, all P value < 0.05); and had less likely to develop into MI oocytes relative to the Small group(β<0, all P value < 0.05). The GLM indicated that AMH, along with Gn total dose, start dose, and Gn days, had significant impact on oocyte and embryo quality. For young patients, age was not a significant influencing factor, but for advanced-age patients, age influenced the outcomes.

Conclusion

Our analysis suggests that for young patients (< 35 years), triggering when there is a high proportion of large or medium follicles results in better quality oocytes, while for older patients (≥ 35 years), it is better to trigger when the proportion of medium follicles is no less than that of small follicles. Further research is required to confirm these findings.

Gonadotropin Stimulation Reduces the Implantation and Live Birth Rate but Not the Miscarriage Rate of Embryos Transferred When Compared to Unstimulated In Vitro Fertilization

Research suggests that gonadotropin stimulation in in vitro fertilization (IVF) treatment affects embryo quality and the endometrium that might influence embryo implantation, placentation and establishment of a viable pregnancy. We assessed the impact of gonadotropin stimulation on implantation, live birth and miscarriage rates per transferred embryo by comparing stimulated and unstimulated IVF treatment. In a cohort of 728 couples, 1310 IVF cycles with successful embryo transfer were analysed; 857 cycles were stimulated with gonadotropins > 75 IU/day (333 poor responder < 4 oocytes; 524 normal responders), and 453 were unstimulated. In total, 1913 fresh cleavage-stage embryos were transferred. Zygote but no embryo selection was performed, and supernumerous zygotes were vitrified. The implantation rate was defined as number of sonographically detected amniotic sacs; live birth rate as number of children born per transferred embryo. Modified mixed effect Poisson regression was used to account for the dependency of cycles and embryos within the same women and the same transfer cycle. Adjustments were made for maternal age, parity, primary or secondary infertility and indication for IVF. Per transferred embryo, implantation rates (rate ratio (RR) 1.37; 95% CI 1.04-1.81; p = 0.028; aRR 1.42; 95% CI 1.10-1.84; p = 0.008) and live birth rates (RR 1.33; 95% CI 0.95-1.86; p = 0.093; aRR 1.38; 95% CI 1.01-1.88; p = 0.044) were higher in NC-IVF compared to cIVF normal responders. Miscarriage did not differ (RR 0.99; 95% CI 0.59-1.65; p = 0.965; aRR 0.90; 95% CI 0.52-1.53 p = 0.698). Similar results were obtained in poor responders. The study suggests an impact of gonadotropin stimulation on the implantation potential of embryos.

Follicular fluid steroid and gonadotropic hormone levels and mitochondrial function from exosomes predict embryonic development

PURPOSE

Human follicular fluid (FF) is a complex biological fluid that contributes to the micro-environment of oocyte development. The aim of this study was to evaluate the role of steroid and gonadotropic hormones levels and mitochondrial function in embryo development during in vitro fertilization cycles.

METHODS

This was a cohort study of 138 women receiving IVF/ICSI, including 136 FF samples from 109 infertile women. FF steroid and gonadotropic hormones levels were tested by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and immunoassays. The mRNA expression levels of mitochondrial electron transport chain (ETC) complex genes from FF exosomes were detected by qPCR.

RESULTS

Analysis of these individual FF concentrations revealed that LH and FSH concentrations were higher in follicles in which the oocyte developed into a top quality (TQ) blastocyst (LH: 9.44 ± 2.32mIU/ml, FSH: 9.32 ± 1.01mIU/ml) than those in which there was a failure of fertilization (LH: 5.30 ± 0.84mIU/ml, FSH: 6.91 ± 0.62mIU/ml). In contrast, follicular cortisone concentrations were lower for oocytes that resulted in a TQ blastocyst (12.20 ± 0.82mIU/ml). The receiver operating characteristic analysis showed that FF LH and FSH levels predicted TQ blastocyst with excellent AUC value of 0.711 and 0.747. Mitochondrial ETC complex I and III mRNA levels were increased in the FF exosomes of TQ blastocyst. Correlation analysis showed that mRNA levels of ETC complex I was positively correlated with LH and FSH levels in FF.

CONCLUSION

The levels of FF steroid and gonadotropic hormones from single follicle can predetermine subsequent embryo development to some extent. Furthermore, impaired exosome mitochondrial dysfunction is a potiential event that causes hormone change in embryo development.

Chinese herbal medicine (Bu-Shen-Tian-Jing Formula) for outcomes of IVF in Chinese patients with polycystic ovary syndrome: a retrospective cohort study

Background

Polycystic ovary syndrome (PCOS) is one of the most common causes of anovulatory infertility. Chinese herbal medicine (CHM) has many advantages in treating PCOS. We conducted a retrospective cohort study to investigate the effects of CHM (Bu-Shen-Tian-Jing Formula, BSTJF) on the outcomes of IVF in Chinese patients with PCOS and the potential underlying mechanism.

Methods

A total of 111 patients with PCOS who undergone IVF between November 2009 and July 2018 were included. Fifty-four patients received a three-month BSTJF therapy before controlled ovarian hyperstimulation, while the other 57 patients didn't. The data of the PCOS patients was collected. Anti-Müllerian hormone (AMH), growth differentiation factor-8 (GDF-8) levels in the follicular fluid were evaluated.

Results

BSTJF helped patients with PCOS to get more retrieved oocytes (P<0.05) and fertilized oocytes (P<0.05). The clinical cumulative pregnancy rate, live birth rate, and term delivery rate were significantly higher in the same stimulated cycle of the PCOS patients with BSTJF treatment (P<0.05). No significant differences existed between the two groups in the rate of fertilization, hospitalization rate of ovarian hyper stimulation syndrome and obstetrical or neonatal complications. BSTJF significantly decreased the AMH levels in the follicular fluids (P<0.05).

Conclusion

BSTJF significantly may improve the outcomes of IVF in Chinese patients with PCOS through decreasing AMH levels in follicular fluids. However, the evidence is limited due to the small sample size and the several potential bias.

Is It Possible to Expand Oocyte Donors by Decreasing Number of Oocytes for Own Use? Insights From a Large Single-Center Study

BACKGROUND

Currently, in China, only women undergoing in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles can donate oocytes to others, but at least 15 oocytes must be kept for their own treatment. Thus, the aim of this study was to determine whether oocyte donation compromises the cumulative live birth rate (CLBR) of donors and whether it is possible to expand oocyte donors' crowd.

METHODS

This was a retrospective cohort study from August 2015 to July 2017 including a total of 2,144 patients, in which 830 IVF-embryo transfer (IVF-ET) patients were eligible for oocyte donation and 1,314 patients met all other oocyte donation criteria but had fewer oocytes retrieved (10-17 oocytes). All 830 patients were advised to donate approximately three to five oocytes to others and were eventually divided into two groups: the oocyte donation group (those who donated) and the control group (those who declined). The basic patient parameters and CLBR, as well as the number of supernumerary embryos after achieving live birth, were compared. These two factors were also compared in all patients (2,144) with oocyte ≥10.

RESULTS

In 830 IVF-ET patients who were eligible for oocyte donation, only the oocyte number was significantly different between two groups, and the donation group had more than the control group (25.49 ± 5.76 vs. 22.88 ± 5.11, respectively; p = 0.09). No significant differences were found between the two groups in other factors. The results indicate that the live birth rate in the donation group was higher than that in the control group (81.31% vs. 82.95%, p = 0.371), without significance. In addition, CLBR can still reach as high as 73% when the oocyte number for own use was 10. Supernumerary embryos also increased as the oocyte number increased in all patients (oocyte ≥10).

CONCLUSIONS

Currently, oocyte donation did not compromise CLBR, and oocyte donation can decrease the waste of embryos. In addition, in patients with 10 oocytes retrieved, the CLBR was still good (73%). Thus, it is possible to expand oocyte donors if the number of oocyte kept for own use was decreased from 15 to 10 after enough communication with patients.

β-Edorphin predict pregnancy outcome of PCOS and DOR women after IVF-ET

PURPOSE

The present study aims to explore whether β-EP in serum (sβ-EP) and follicular fluid (ffβ-EP) could predict the in vitro fertilization (IVF) outcomes of patients with polycystic ovary syndrome (PCOS) and diminished ovarian reserve (DOR).

METHODS

90 PCOS women, 50 DOR women, and 100 women with normal ovarian function (control group), who were all undergoing an IVF-embryo transfer trial, were included in the study. Biochemical characteristics, anti-Mullerian hormone (AMH), sβ-EP, ffβ-EP, embryo formation, and pregnancy indicators were assessed in all women. The correlations of AMH and β-EP with oocyte quality were analyzed. Population-based and age-category stratified receiver operating characteristic (ROC) curve analysis of AMH and β-EP for predicting pregnancy and live birth were performed.

RESULTS

Compared with the control group, the PCOS group had higher antral follicle count, testosterone, luteinizing hormone, AMH, sβ-EP, and ffβ-EP, which were lower in the DOR group. Meanwhile, the PCOS and DOR groups had higher cycle cancellation and miscarriage rates, and lower high quality embryo numbers. Correlation analysis showed that the oocyte quality were positively correlated with AMH, sβ-EP, and ffβ-EP. The population-based and age-stratified ROC curve analysis showed that sβ-EP and ffβ-EP had high sensitivity and specificity to predict pregnancy and live birth. Meanwhile, age-stratified AMH enhanced the sensitivity for prediction of live birth after IVF.

CONCLUSION

sβ-EP and ffβ-EP are different among women with PCOS, DOR, and normal ovarian function. β-EP can be used as a good predictor of clinical pregnancy and live birth after IVF.

Oocyte Selection for In Vitro Embryo Production in Bovine Species: Noninvasive Approaches for New Challenges of Oocyte Competence

Simple Summary

The efficiency of producing embryos using in vitro technologies in cattle species remains lower when compared to mice, indicating that the proportion of female gametes that fail to develop after in vitro manipulation is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting embryo production, the precise identification of noninvasive markers that predict oocyte competence is of major interest. The aim of this review was to explore the current literature on different noninvasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, a large slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated with better embryonic development. In addition, the combination of oocyte and zygote selection, spindle imaging, and the anti-Stokes Raman scattering microscopy together with studies decoding molecular cues in oocyte maturation have the potential to further optimize the identification of oocytes with better developmental competence for in vitro technologies in livestock species.

Abstract

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30–40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of noninvasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different noninvasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated with better competence. In addition, the combination of oocyte and zygote selection via brilliant cresyl blue (BCB) test, spindle imaging, and the anti-Stokes Raman scattering microscopy together with studies decoding molecular cues in oocyte maturation have the potential to further optimize the identification of oocytes with better developmental competence for in-vitro-derived technologies in livestock species.

Clinical Application of AMH Measurement in Assisted Reproduction

Anti-Müllerian hormone reflects the continuum of the functional ovarian reserve, and as such can predict ovarian response to gonadotropin stimulation and be used to individualize treatment pathways to improve efficacy and safety. However, consistent with other biomarkers and age-based prediction models it has limited ability to predict live birth and should not be used to refuse treatment, but rather to inform counselling and shared decision making. The use of absolute clinical thresholds to stratify patient phenotypes, assess discordance and individualize treatment protocols in non-validated algorithms combined with the lack of standardization of assays may result in inappropriate classification and sub-optimal clinical decision making. We propose that holistic baseline phenotyping, incorporating antral follicle count and other patient characteristics is critical. Treatment decisions driven by validated algorithms that use ovarian reserve biomarkers as continuous measures, reducing the risk of misclassification, are likely to improve overall outcomes for our patients.