Controlled ovarian stimulation for in-vitro fertilization

Stereological study of organelle distribution in human mature oocytes

The ultrastructure of human oocytes has been described only qualitatively. To offer a precise organelle spatial distribution and organelle volume during the main maturation stages, we previously conducted stereological studies on prophase-I (GV) and metaphase-I (MI) oocytes, and here we present results on metaphase-II (MII) oocytes. Five donor oocytes from different donors were processed for transmission electron microscopy, and quantification of organelle distribution was performed using point-counting stereology. Statistical tests compared the means of the relative volumes occupied by organelles among oocyte regions. The most abundant organelles were elements of the smooth endoplasmic reticulum (SER), such as SER small vesicles, SER medium vesicles, SER large vesicles and SER isolated tubules, along with mitochondria, followed by SER tubular aggregates, cortical vesicles and lysosomes. Significant differences between oocyte regions were found for lysosomes, cortical vesicles and SER large vesicles. Comparisons of MII oocytes to previous findings in GV and MI oocytes evidenced specific patterns of organelle distribution and relative volumes. This final evaluation thus enables to track organelle spatial reorganization across oocyte stages, which, in addition to gathered knowledge, may be useful to assist in improvements of stimulation protocols, in-vitro maturation media and cryopreservation techniques.

Change of HeART: Cardiovascular Implications of Assisted Reproductive Technology

Cardiovascular (CV) disease is the leading cause of death in women, and it may manifest differently than in men, in part related to sex-specific CV risk factors. In females, assisted reproductive technologies (ARTs) are commonly used to treat infertility, and they utilize controlled ovarian stimulation involving the administration of exogenous sex hormones. ARTs, and especially controlled ovarian stimulation, have been associated with an increased pregnancy and short-term CV risk, although the long-term CV implications of these treatments in individuals treated with ARTs and their offspring remain unclear. This review endeavors to provide a comprehensive examination of what is known about the relationship between ART and CV outcomes for females treated with ARTs, as well as their offspring, and recommendations for future research. Novel insights into female-specific CV risk factors are critical to reduce the disproportionate burden of CV disease in Canadian women. ART has revolutionized reproductive medicine, offering hope to millions of individuals with infertility worldwide, and a further understanding of the CV implications of this important sex-specific CV risk factor is warranted urgently.

The preimplantation genetic testing clinical outcomes of biopsy on vitrification-warming embryos: A retrospective study

AIM

The objective of this study was to assess whether PGT conducted with previously untested vitrified embryos affect the clinical outcomes.

METHODS

A total of 49 patients who underwent biopsy on vitrification-warming embryos for PGT were enrolled from January 2016 to January 2019. The cleavage-stage embryos were thawed and cultured into the blastocyst stage for biopsy. During this period, 195 patients underwent routine PGT and FET, whose embryos were biopsied before frozen were used as the control group. The clinical outcomes were further compared between the two groups after a 1:2 PSM.

RESULTS

There were 47 transferable blastocysts in 30 patients, while 19 patients without transferable embryos, who performed biopsy on vitrification-warming embryos for PGT. During this study period, 27 patients have already underwent FET with the clinical pregnancy rate was 66.7% (18/27). After 1:2 PSM, 24 patients in the biopsy on vitrification-warming embryo group and 48 patients in the control group were compared, the clinical pregnancy rate (68.8% vs. 70.8%, p = 0.86), miscarriage rate (18.2% vs. 11.8%, p = 0.86), or live birth rate (52.1% vs. 62.5%, p = 0.40) had no significant difference. And the transferable blastocyst rate or the clinical pregnancy rate in the vitrification-warming cleavage-stage embryo group was not significantly different from those in the vitrification-warming blastocyst group. In addition, the PGT clinical outcomes of biopsy on vitrification-warming embryos had no significant difference between IVF-fertilized embryos and ICSI-fertilized embryos.

CONCLUSION

Biopsy on the vitrification-warming embryos with a dual vitrified cryopreservation does not affect the embryo quality or the PGT clinical outcomes.

Application of ultrasound markers measured at different time points of COH cycle in the prediction of ovarian response for individualised ovulation induction

The purpose of this study was to evaluate the predictive value of ultrasound markers measured at different time points of the controlled ovarian hyperstimulation (COH) cycle on ovarian response and outcome indicators in the IVF-ET cycle. According to the oestrogen level and the number of retrieved oocytes, patients who planned for COH treatment were separated into low-response group, normal and high-response group. The ovarian stromal artery flow parameters on the day of pituitary down-regulation, day 1, day 7, day 10, and the day of hCG injection were collected prospectively. We also have collected the data of cumulus oophorus count on the day of hCG injection by transvaginal sonography. Compared with the low-response group, on the first day of the COH cycle PI, RI, and S/D were lower in the high-response group than they were in the low-response group (p < .05). PSV and EDV were significantly higher in the high-response group than they were in the low-response group (p < .01), and the PSV on the first day of the COH cycle have statistical significance in predicting the number of high-quality embryos. The number of cumulus oophorus on the day of hCG injection has statistical significance in predicting the number of oocytes retrieved and fertilised oocytes. We conclude that the ovarian stromal artery flow parameters on the first day of the COH cycle and cumulus oophorus count on hCG injection day can serve as efficient indicators for an early assessment of ovarian response and individualised ovulation induction.IMPACT STATEMENTWhat is already known on this subject? AMH, AFC, and the age of the patient are well-known effective parameters for the evaluation of ovarian response, but these are insufficient and full of individual differences. Some researchers have investigated the value of colour Doppler ultrasound and cumulus oophorus in assessing ovarian response, but no definitive conclusion has been reached.What do the results of this study add? The hemodynamic parameters of ovarian stromal artery on the first day of the COH cycle and the number of cumulus oophorus on the day of hCG injection detected by Transvaginal Colour Doppler Sonography (TV-CDS) could be used to predict the ovarian response.What are the implications of these findings for clinical practice and/or further research? Ovarian stromal artery flow parameters and cumulus oophorus detected by TV-CDS can potentially be offered as a complementary parameter for ovarian reserve.

Clinical Relevance of Secreted Small Noncoding RNAs in an Embryo Implantation Potential Prediction at Morula and Blastocyst Development Stages

Despite the improvements in biotechnological approaches and the selection of controlled ovarian hyperstimulation protocols, the resulting pregnancy rate from in vitro fertilization (IVF) protocols still does not exceed 30-40%. In this connection, there is an acute question of the development of a non-invasive, sensitive, and specific method for assessing the implantation potential of an embryo. A total of 110 subfertile couples were included in the study to undergo the IVF/ICSI program. Obtained embryos for transfer into the uterine cavity of patient cohort 1 (n = 60) and cohort 2 (n = 50) were excellent/good-quality blastocysts, and small noncoding RNA (sncRNA) content in the corresponding spent culture medium samples at the morula stage (n = 43) or at the blastocyst stage (n = 31) was analyzed by deep sequencing followed by qRT-PCR in real time. Two logistic regression models were developed to predict the implantation potential of the embryo with 100% sensitivity and 100% specificity: model 1 at the morula stage, using various combinations of hsa_piR_022258, hsa-let-7i-5p, hsa_piR_000765, hsa_piR_015249, hsa_piR_019122, and hsa_piR_008112, and model 2 at the blastocyst stage, using various combinations of hsa_piR_020497, hsa_piR_008113, hsa-miR-381-3p, hsa_piR_022258, and hsa-let-7a-5p. Protein products of sncRNA potential target genes participate in the selective turnover of proteins through the ubiquitination system and in the organization of the various cell cytoskeleton and nucleoskeleton structures, regulating the activity of the Hippo signaling pathway, which determines the fate specification of the blastomers.

Correlation of TP53 (rs1625895), TP73 (rs3765730), MMP9 (rs17576), and MTHFR (rs868014) polymorphisms with low ovarian reserve

OBJECTIVE

To investigate the influence of the Single Nucleotide Polymorphisms (SNPs) TP53 rs1625895, TP73 rs3765730, MMP9 rs17576, and MTHFR rs868014 on ovarian reserve (OR) in infertile patients.

STUDY DESIGN

A prospective cross-sectional study was carried out in 145 infertile women. The patients were divided into two groups according to ovarian reserve, characterized by association between AMH levels and AFC:After patient distribution, both groups were compared (LOR X NOR) regarding the genotypes of the SNPs TP53 T/C rs1625895, TP73 G/A rs3765730, MMP9 Gln/Arg rs17576, and MTHFR A/G rs868014.

RESULT(S)

The frequency of the TP53-T/T genotype was greater in the LOR and the TP53-C/C genotype was more frequent in patients with NOR. This association was confirmed by the frequency of alleles, where the presence of the T allele was significantly higher in patients who exhibited LOR (P = 0.0003). The frequency of the TP73-G/G genotype and of the G allele was higher in the LOR group (P = 0.01). Considering the MMP9 gene, the frequency of the Gln/Gln genotype was higher in the LOR group. However, the Gln/Arg genotype and the Arg allele prevailed in the NOR group (P = 0.006). The frequency of the MTHFR-A/A genotype was higher in the LOR group, whereas that of the MTHFR-GG genotype was higher in the NOR group. The presence of allele A was significantly higher in the LOR group (P = 0.002). The regression analysis shows that patients who present the TP53-T/T, TP73-G/G, MMP9-Gln/Gln, and MTHFR-A/A genotypes are 3.6X, 3.1X, 3.2X, and 3.7X more likely of having LOR, respectively. In addition, the association of the TP53/TT + TP73/GG genotypes increased the chance of women being included in the LOR group in 5.7-fold.

CONCLUSION(S)

The genotypes TP53-T/T, TP73-G/G, MMP9-Gln/Gln, and MTHFR-A/A increase the chance of women to exhibit LOR. These polymorphisms could be useful as genetic markers of low ovarian reserve in infertile patients.

The FSHR G-29A variant is not associated with the ovarian response to exogenous FSH stimulation

A common genetic variant in the follicle stimulating hormone receptor gene (FSHR) 5'-untranslated region has been previously reported to influence FSHR gene expression. However, studies on the ovarian response to exogenous gonadotropin stimulation are limited. The aim of this study was to evaluate the association of variants at positions -29 of the FSHR gene with the ovarian response to exogenous FSH stimulation in Chinese women. The genotypes of the FSHR gene were assayed using the Sequenom MassARRAY system. Total RNA and protein was extracted from granulosa cells, and FSHR expression at the mRNA and protein levels was assessed using quantitative PCR and western blotting. Our data revealed that there was no association between the FSHR genotype at the -29 position and the outcome of controlled ovarian stimulation. The expression of FSHR, at both the mRNA and protein levels, was similar amongst the different FSHR genotypes assessed, but was significantly reduced in the low responders. These results indicate that the variants caused by mutations at position -29 are not associated with ovarian response, and the low ovarian response to gonadotropin stimulation may be caused by decreased FSHR expression.

Small Noncoding RNA Signatures for Determining the Developmental Potential of an Embryo at the Morula Stage

As part of the optimization of assisted reproductive technology programs, the aim of the study was to identify key small noncoding RNA (sncRNA) molecules that participate in maternal-to-zygotic transition and determine development potential and competence to form a healthy fetus. Small RNA deep sequencing followed by quantitative real-time RT-PCR was used to profile sncRNAs in 50 samples of spent culture medium from morula with different development potentials (no potential (degradation/developmental arrest), low potential (poor-quality blastocyst), and high potential (good/excellent quality blastocyst capable of implanting and leading to live birth)) obtained from 27 subfertile couples who underwent in vitro fertilization. We have shown that the quality of embryos at the morula stage is determined by secretion/uptake rates of certain sets of piRNAs and miRNAs, namely hsa_piR_011291, hsa_piR_019122, hsa_piR_001311, hsa_piR_015026, hsa_piR_015462, hsa_piR_016735, hsa_piR_019675, hsa_piR_020381, hsa_piR_020485, hsa_piR_004880, hsa_piR_000807, hsa-let-7b-5p, and hsa-let-7i-5p. Predicted gene targets of these sncRNAs included those globally decreased at the 8-cell–morula–blastocyst stage and critical to early embryo development. We show new original data on sncRNA profiling in spent culture medium from morula with different development potential. Our findings provide a view of a more complex network that controls human embryogenesis at the pre-implantation stage. Further research is required using reporter analysis to experimentally confirm interactions between identified sncRNA/gene target pairs.