Improvement of pregnancy outcome by extending embryo culture in IVF-ET during clinical application

DTLR-CS: Deep tensor low rank channel cross fusion neural network for reproductive cell segmentation

In recent years, with the development of deep learning technology, deep neural networks have been widely used in the field of medical image segmentation. U-shaped Network(U-Net) is a segmentation network proposed for medical images based on full-convolution and is gradually becoming the most commonly used segmentation architecture in the medical field. The encoder of U-Net is mainly used to capture the context information in the image, which plays an important role in the performance of the semantic segmentation algorithm. However, it is unstable for U-Net with simple skip connection to perform unstably in global multi-scale modelling, and it is prone to semantic gaps in feature fusion. Inspired by this, in this work, we propose a Deep Tensor Low Rank Channel Cross Fusion Neural Network (DTLR-CS) to replace the simple skip connection in U-Net. To avoid space compression and to solve the high rank problem, we designed a tensor low-ranking module to generate a large number of low-rank tensors containing context features. To reduce semantic differences, we introduced a cross-fusion connection module, which consists of a channel cross-fusion sub-module and a feature connection sub-module. Based on the proposed network, experiments have shown that our network has accurate cell segmentation performance.

Nomogram to predict FSH starting dose in poor ovarian response women in progestin primed ovarian stimulation protocol

Prediction of individual ovarian response to exogenous gonadotropin is a cornerstone for success and safety in all controlled ovarian stimulation (COS) protocols. Providing the best FSH starting dose according to each woman's own characteristics is the key to the success of individualized treatment. The objective of this investigation was to evaluate the potential application of a novel nomogram based on antral follicle counting (AFC), anti-Müllerian hormone (AMH) and body mass index (BMI) as a tool to optimize the follicle-stimulating hormone (FSH) starting dose in women with poor ovarian response in in-vitro fertilization (IVF)/intra-cytoplasmic sperm injection (ICSI) cycles in progestin-primed ovarian stimulation (PPOS). We performed a retrospective analysis involving 130 poor ovarian responders undergoing IVF/ICSI cycles in a PPOS protocol from June 2017 to February 2019 in our reproductive center. The individual FSH starting dose was selected according to patients' clinical history and characteristics. The influence of variables including age, BMI, AMH and AFC on the FSH starting dose was assessed through multiple regression analysis. We used the variables reaching the statistical significance for calculation for the final predictive model. In the univariate analysis, BMI, AMH and AFC were significant (P < 0.05) predictors of FSH starting dose, age was canceled. In the multivariate analysis, BMI, AMH and AFC remained significant (P < 0.05). According to the nomogram, 118 patients (90.77% of 130) would have received a higher FSH starting dose and 12 patients (9.23% of 130) a lower FSH starting dose than practice dose. The application of the nomogram based on three variables easily determined in clinical practice: BMI, AMH and AFC would lead to a more tailored FSH starting dose in women with poor ovarian response.

Clinical Application of Double Ovulation Stimulation in Patients with Diminished Ovarian Reserve and Asynchronous Follicular Development Undergoing Assisted Reproduction Technology

OBJECTIVE

This study aimed to compare the clinical effects of double ovulation stimulation (DouStim) applied during the follicular and luteal phases with the antagonist protocol in patients with diminished ovarian reserve (DOR) and asynchronous follicular development undergoing assisted reproductive technology (ART).

METHODS

The clinical data of patients with DOR and asynchronous follicular development receiving ART from January 2020 to December 2021 were retrospectively analyzed. The patients were divided into two groups according to their ovulation stimulation protocol: DouStim group (n=30) and antagonist group (n=62). Assisted reproduction and clinical pregnancy outcomes were compared between the two groups.

RESULTS

In the DouStim group, the number of oocytes retrieved, metaphase II (MII) oocytes, two-pronuclei (2PN), day 3 (D3) embryos, D3 high-quality embryos as well as blastocyst formation, implantation, and human chorionic gonadotropin-positive rates were significantly greater than those in the antagonist group (all P<0.05). No significant differences were found in MII, fertilization, or continued pregnancy rates at the first frozen embryo transfer (FET), in-vitro fertilization (IVF) cancellation, or early medical abortion rates between the groups (all P>0.05). Except for the early medical abortion rate, the DouStim group generally had favorable outcomes. In the DouStim group, the dosage and duration of gonadotropin and the fertilization rate were significantly greater in the first ovulation stimulation induction than in the second ovulation stimulation induction (P<0.05).

CONCLUSION

The DouStim protocol efficiently and economically obtained more mature oocytes and high-quality embryos for patients with DOR and asynchronous follicular development.

Ultrastructure of mitochondria of human oocytes in different clinical conditions during assisted reproduction

Infertility affects around 8% of couples with a slight change in percentage in the last years. Despite the significant efforts made in Assisted Reproductive Technologies (ARTs) in handling this disorder, oocyte quality remains a crucial factor for a positive outcome. A better understanding of the dynamics underlying oocyte maturation, fertilization, and embryo development remains one of the main areas for progress in the ARTs field. Mitochondria are believed to play an essential role in these processes. Mitochondria have a crucial part in producing energy for oocyte maturation and embryo development throughout precise cellular functions comprising Ca²⁺ homeostasis regulation, glycolysis, amino acid and fatty acid metabolism, and regulation of apoptosis. Recent studies suggest that mitochondrial structure, content, and function may be related to oocyte competence, embryo viability, and implantation success during ARTs. Their defects could lead to low fertilization rates and embryonic development failure. This review aimed to provide an overview of the available literature data surrounding the correlation between changes at ultrastructural level of mitochondria or correlated-mitochondrial aggregates and oocyte quality and ARTs treatments. Our reported data demonstrated that oocyte mitochondrial ultrastructural alterations could be partial or complete recovery during the early embryo stages. However, these changes could persist as quiescent during the pre-implantation embryo development, causing abnormalities that become evident only during fetal and postnatal life. These factors led to consider the mitochondria as a crucial marker of oocyte and embryo quality, as well as a strategic target for further prospective therapeutical approaches.

Dynamics and clinical relevance of maternal mRNA clearance during the oocyte-to-embryo transition in humans

Maternal mRNA clearance is an essential process that occurs during maternal-to-zygotic transition (MZT). However, the dynamics, functional importance, and pathological relevance of maternal mRNA decay in human preimplantation embryos have not yet been analyzed. Here we report the zygotic genome activation (ZGA)-dependent and -independent maternal mRNA clearance processes during human MZT and demonstrate that subgroups of human maternal transcripts are sequentially removed by maternal (M)- and zygotic (Z)-decay pathways before and after ZGA. Key factors regulating M-decay and Z-decay pathways in mouse have similar expression pattern during human MZT, suggesting that YAP1-TEAD4 transcription activators, TUT4/7-mediated mRNA 3ʹ-oligouridylation, and BTG4/CCR4-NOT-induced mRNA deadenylation may also be involved in the regulation of human maternal mRNA stability. Decreased expression of these factors and abnormal accumulation of maternal transcripts are observed in the development-arrested embryos of patients who seek assisted reproduction. Defects of M-decay and Z-decay are detected with high incidence in embryos that are arrested at the zygote and 8-cell stages, respectively. In addition, M-decay is not found to be affected by maternal TUBB8 mutations, although these mutations cause meiotic cell division defects and zygotic arrest, which indicates that mRNA decay is regulated independent of meiotic spindle assembly. Considering the correlations between maternal mRNA decay defects and early developmental arrest of in vitro fertilized human embryos, M-decay and Z-decay pathway activities may contribute to the developmental potential of human preimplantation embryos.

How maternal RNA clearance is regulated in human preimplantation embryos is unclear. Here, the authors show there is a potential correlation between maternal mRNA decay defects and early developmental arrest from in vitro fertilized human embryos, suggesting that M-decay and Z-decay pathways may regulate such early development.

Pre-Implantation Mouse Embryos Cultured In Vitro under Different Oxygen Concentrations Show Altered Ultrastructures

Assisted Reproductive Technologies routinely utilize different culture media and oxygen (O2) concentrations to culture human embryos. Overall, embryos cultured under physiological O2 tension (5%) have improved development compared to embryos cultured under atmospheric O2 conditions (20%). The mechanisms responsible for this remain unclear. This study aimed to evaluate the effect of physiologic (5%) or atmospheric O2 (20%) tension on the microscopic ultrastructure of pre-implantation mouse embryos using Transmission Electron Microscopy (TEM). Embryos flushed out of the uterus after natural mating were used as the control. For use as the control, 2-cells, 4-cells, morulae, and blastocysts were flushed out of the uterus after natural fertilization. In vitro fertilization (IVF) was performed using potassium simplex optimized medium (KSOM) under different O2 tensions (5% and 20%) until the blastocyst stage. After collection, embryos were subjected to the standard preparative for light microscopy (LM) and TEM. We found that culture in vitro under 5% and 20% O2 results in an increase of vacuolated shaped mitochondria, cytoplasmic vacuolization and presence of multi-vesicular bodies at every embryonic stage. In addition, blastocysts generated by IVF under 5% and 20% O2 showed a lower content of heterochromatin, an interruption of the trophectodermal and inner cell mass cell membranes, an increased density of residual bodies, and high levels of glycogen granules in the cytoplasm. In conclusion, this study suggests that in vitro culture, particularly under atmospheric O2 tension, causes stage-specific changes in preimplantation embryo ultrastructure. In addition, atmospheric (20%) O2 is associated with increased alterations in embryonic ultrastructure; these changes may explain the reduced embryonic development of embryos cultured with 20% O2.

Establishment of predictive model for analyzing clinical pregnancy outcome based on IVF-ET and ICSI assisted reproductive technology

In order to explore the predictive model for analyzing clinical pregnancy outcomes based on IVF-ET (in vitro fertilization and embryo transfer) and ICSI (Intracytoplasmic sperm injection) assisted reproductive technology (ART). Methods: this study selected the embryo transfer (fresh) patients who received IVF-ET or ICSI treatment in the First Affiliated Hospital of Guangxi Medical University as the subjects. Moreover, the controlled ovarian stimulation (COS) and follow-up were conducted to collect relevant data for analysis, and finally a prediction model was established. Results: The results showed that the patients were divided into different ovarian response groups at first. The age, bFSH and bFSH/bLH were the highest in the poor ovarian response group (POR), followed by the normal ovarian response group (NOR) and the lowest in the high ovarian response group (HOR). The area under the ROC curve was 0.669 according to the predictive model of pregnancy-related factors. The confidence interval of 94% was 0.629–0.697, with statistical significance (P = 0.000, P < 0.01). Conclusion: it can be concluded that in clinical pregnancy, for many related factors, regression equation can be used to establish a prediction model to diagnose the success rate of pregnancy. In conclusion, a prediction model can be built based on the relevant experimental results, to provide experimental reference ideas for increasing the success rate of ART in late clinical pregnancy, which is of great research significance.