Predictive value of seminal oxidation-reduction potential analysis for reproductive outcomes of ICSI.

RESEARCH QUESTION: Is seminal oxidation-reduction potential (ORP) clinically relevant to reproductive outcome? DESIGN: Prospective observational study including a total of 144 couples who had an intracytoplasmic sperm injection (ICSI) cycle between June 2018 and December 2020. The study included patients undergoing fresh ICSI cycles with autologous gametes. Cycles that had day 3 embryo transfers and cryopreservation cycles were excluded. There was no restriction on patients with severe male infertility; couples with unexplained infertility and unexplained male infertility were included, those with azoospermia were excluded. Semen analysis, seminal ORP as determined by means of the MiOXSYS system, sperm DNA fragmentation (SDF) and reproductive outcomes (fertilization, blastocyst development, clinical pregnancy and live birth) were determined. RESULTS: Seminal ORP was significantly negatively correlated with fertilization rate (r = -0.267; P = 0.0012), blastocyst development rate (r = -0.432; P < 0.0001), implantation/clinical pregnancy (r = -0.305; P = 0.0003) and live birth (r = -0.366; P < 0.0001). Receiver operating characteristic curve analysis showed significant predictive power for ORP for fertilization (≥80%; area under the curve [AUC] 0.652; P = 0.0012), blastocyst development rate (≥60%; AUC 0.794; P < 0.0001), implantation/clinical pregnancy (AUC 0.680; P = 0.0002) and live birth (AUC 0.728; P < 0.0001). Comparable results were obtained for SDF (fertilization: AUC 0.678; blastocyst development: AUC 0.777; implantation/clinical pregnancy: AUC 0.665; live birth: AUC 0.723). Normal sperm morphology showed the lowest predictive power for all reproductive outcome parameters. With male age as confounding factor, ORP (cut-off value of 0.51 mV/106 sperm/ml) has significant (P < 0.04667) effects on odds ratios for all reproductive outcome parameters. Multivariate logistic regression to investigate potential seminal and female confounding factors revealed that seminal ORP significantly (P < 0.0039; P < 0.0130) affects reproductive outcome. CONCLUSION: Seminal ORP is relevant for good fertilization, blastocyst development, implantation, clinical pregnancy and live birth.

Interplay of Oxidants and Antioxidants in Mammalian Embryo Culture System.

One principal purpose of assisted reproductive technology (ART) is to produce viable and good quality embryos. However, a variety of environmental factors may induce epigenetic changes in the embryo. Moreover, laboratory conditions including the culture media may also affect embryo development. Therefore, media change is an important factor in maintaining proper oxidant/antioxidant balance during embryo culture. Alterations in the oxidant/antioxidant balance are related to various cellular responses such as an increase in the level of reactive oxygen species (ROS) and consequent lipid peroxidation (LPO), DNA damage, and apoptosis. The current study focuses on the role of external factors on embryo culture and the ability of antioxidants to enhance in vitro fertilization (IVF) outcomes. Indeed, an optimization of media culture by the addition of enzymatic and nonenzymatic antioxidants in animal models and human embryos in ART has been updated in this study, with an emphasis on comparing the available results and their possible reasons.

Oxidative Stress-Induced Male Infertility: Role of Antioxidants in Cellular Defense Mechanisms.

Male infertility is linked to several environmental and mutagenic factors. Most of these factors, i.e., lifestyle, radiations, and chemical contaminations, work on the fundamental principles of physics, chemistry, and biology. Principally, it may induce oxidative stress (OS) and produce free radicals within the cells. The negative effect of OS may enhance the reactive oxygen species (ROS) levels in male reproductive organs and impair basic functions in a couple's fertility. Evidence suggests that infertile men have significantly increased ROS levels and a reduced antioxidant capacity compared with fertile men. Although, basic spermatic function and fertilizing capacity depend on a delicate balance between physiological activity of ROS and antioxidants to protect from cellular oxidative injury in sperm, that is essential to achieve pregnancy. The ideal oxidation-reduction (REDOX) equilibrium requires a maintenance of a range of ROS concentrations and modulation of antioxidants. For this reason, the chapter focuses on the effects of ROS in sperm functions and the current concepts regarding the benefits of medical management in men with diminished fertility and amelioration of the effect to improve sperm function. Also, this evidence-based study suggests an increasing rate of infertility that poses a global challenge for human health, urging the need of health care professionals to offer a correct diagnosis, comprehension of the process, and an individualized management of the patients.

Comparative study of fertility parameters in vitrified human spermatozoa in the presence or absence of EmbryORP® : A novel antioxidant.

The cryopreservation of spermatozoa has the main purpose of preserving male fertility. However, current preservation techniques have shown to produce lesions in the structure and alter sperm functions, probably due to the production of reactive oxygen species (ROS) during cryopreservation. To overcome the damage provoked by ROS, we introduced a novel antioxidant called EmbryORP® in a vitrification protocol and compared eight fertility parameters: motility, viability, morphology, concentration, the semen pH, the oxidation-reduction potential (ORP), the spontaneous acrosomal reaction (AR) and the mitochondrial membrane potential (MMP), in the presence or absence of EmbryORP® . We analysed 20 samples from healthy human sperm donors and observed that the antioxidant significantly decreased the semen pH as well as the MMP and the ORP affecting the balance of ROS. The antioxidant also lowered the motility and viability of the cells, but preserved the acrosome and sperm morphology in general. We concluded that EmbryORP® lowered the ORP, but to a suboptimal level that may be harmful to spermatozoa. Despite these results, our work opens new perspectives on how to improve cryopreservation media. Therefore, we recommend exploring the EmbryORP® potential benefit by reducing its concentration or changing the exposure time during the cryopreservation protocol.

Oocyte maturation arrest produced by TUBB8 mutations: impact of genetic disorders in infertility treatment.

Oocyte maturation defect is a challenging situation in the management of infertility, the etiology may be related to endocrine causes, protocols used in ovarian stimulation, oocyte intrinsic defects or procedures in embryology laboratory. We report three Mexican females in treatment for primary infertility with non-mature oocytes after ovary stimulation and oocyte capture in whom a genetic diagnosis of TUBB8-oocyte maturation defect was revealed by exome sequencing. Two couples achieved pregnancies though oocyte donation after establishing the genetic etiology. Our results expand the role of TUBB8-disorders in patients of non-Asian ethnicity. Oocyte maturation defects of monogenic origin are a growing group of disorders that endocrinologists and reproductive medicine specialists should be aware in order to provide referral to genetics for establish a correct and opportune diagnosis.

Uterine flushings from women treated with levonorgestrel affect sperm functionality in vitro.

Levonorgestrel (LNG), a synthetic 19 nor-testosterone derivative, is widely used for emergency contraception. It is well known that LNG prevents ovulation only when given prior to the surge of serum luteinizing hormone (LH) during the periovulatory phase of the menstrual cycle. This observation suggests that LNG, given its contraceptive efficacy, has additional effects other than those affecting ovulation. In this study, we have evaluated the effects on human sperm functionality of uterine flushings (UF) obtained from women at day LH + 1 of a control cycle (CTR-LH + 1) and after receiving LNG (LNG-LH + 1) two days before the surge of LH. Human sperm from normozoospermic donors were incubated with UF and protein tyrosine phosphorylation, sperm motility, acrosome reaction as well as zona pellucida (ZP) binding capacity were assessed. A significant decrease in total motility and tyrosine phosphorylation accompanied by an increase on spontaneous acrosome reaction was observed when sperm were incubated in the presence of LNG-LH + 1. None of these effects were mimicked by purified glycodelin A (GdA). Moreover, the addition of UF obtained during the periovulatory phase from LNG-treated women or the presence of purified GdA significantly decreased sperm-ZP binding. The data were compatible with changes affecting sperm capacitation, motility and interaction with the ZP. These results may offer evidence on additional mechanisms of action of LNG as an emergency contraceptive.

Human sperm degradation of zona pellucida proteins contributes to fertilization.

BACKGROUND: The mammalian oocyte extracellular matrix known as the zona pellucida (ZP) acts as a barrier to accomplish sperm fusion with the female gamete. Although penetration of the ZP is a limiting event to achieve fertilization, this is one of the least comprehended stages of gamete interaction. Even though previous studies suggest that proteases of sperm origin contribute to facilitate the passage of sperm through the ZP, in human this process is not yet fully understood. The aim of this study was to determine the ability of human sperm to degrade recombinant human ZP (rhZPs) proteins and to characterize the proteases involved in this process. METHODS: Purified rhZP2, rhZP3 and rhZP4 proteins were incubated with capacitated sperm and the proteolytic activity was determined by Western blot analysis. To further characterize the proteases involved, parallel incubations were performed in the presence of the protease inhibitors o-phenanthroline, benzamidine and MG-132 meant to block the activity of metalloproteases, serine proteases and the proteasome, respectively. Additionally, protease inhibitors effect on sperm-ZP binding was evaluated by hemizona assay. RESULTS: The results showed that rhZPs were hydrolyzed in the presence of capacitated sperm. O-phenanthroline inhibited the degradation of rhZP3, MG-132 inhibited the degradation of rhZP4 and benzamidine inhibited the degradation of the three proteins under investigation. Moreover, hemizona assays demonstrated that sperm proteasome inhibition impairs sperm interaction with human native ZP. CONCLUSIONS: This study suggests that sperm proteasomes could participate in the degradation of ZP, particularly of the ZP4 protein. Besides, metalloproteases may be involved in specific degradation of ZP3 while serine proteases may contribute to unspecific degradation of the ZP. These findings suggest that localized degradation of ZP proteins by sperm is probably involved in ZP penetration and may be of help in understanding the mechanisms of fertilization in humans.

Artificial Intelligence in Andrology: From Semen Analysis to Image Diagnostics.

Artificial intelligence (AI) in medicine has gained a lot of momentum in the last decades and has been applied to various fields of medicine. Advances in computer science, medical informatics, robotics, and the need for personalized medicine have facilitated the role of AI in modern healthcare. Similarly, as in other fields, AI applications, such as machine learning, artificial neural networks, and deep learning, have shown great potential in andrology and reproductive medicine. AI-based tools are poised to become valuable assets with abilities to support and aid in diagnosing and treating male infertility, and in improving the accuracy of patient care. These automated, AI-based predictions may offer consistency and efficiency in terms of time and cost in infertility research and clinical management. In andrology and reproductive medicine, AI has been used for objective sperm, oocyte, and embryo selection, prediction of surgical outcomes, cost-effective assessment, development of robotic surgery, and clinical decision-making systems. In the future, better integration and implementation of AI into medicine will undoubtedly lead to pioneering evidence-based breakthroughs and the reshaping of andrology and reproductive medicine.

Clinical aspects of oocyte retrieval and embryo transfer: tips and tricks for the novice and the expert.

Oocyte retrieval (ovum pick-up) and embryo transfer (ET) are essential steps in in-vitro fertilization and intracytoplasmic sperm injection and over the years, the two procedures were developed in order to improve the clinical outcome. Many suggestions were proposed and applied before, during and after oocyte retrieval such as timing of HCG trigger, pre-operative pelvic scan, vaginal cleansing, type of anesthesia, type and gauge of aspiration needles, aspiration pressure, follicle flushing, and the need for prophylactic antibiotics. Similarly, many steps were suggested and implemented before, during and after ET including patient's position, type of anesthesia/analgesia, dummy (mock) ET, ultrasound-guidance, HCG injection in the uterine cavity, use of relaxing agents, full bladder, removal of the cervical mucus, flushing the cervix with culture medium, type of ET catheter, embryo loading techniques, site of embryo deposition, the use of adherence compounds, as well as bed rest after ET. Complications were also reported with oocyte retrieval and ET. The aim of this review is to evaluate the current practice of these two procedures in the light of available evidence.

Oxidative Stress and Assisted Reproduction: A Comprehensive Review of Its Pathophysiological Role and Strategies for Optimizing Embryo Culture Environment.

Oxidative stress (OS) due to an imbalance between reactive oxygen species (ROS) and antioxidants has been established as an important factor that can negatively affect the outcomes of assisted reproductive techniques (ARTs). Excess ROS exert their pathological effects through damage to cellular lipids, organelles, and DNA, alteration of enzymatic function, and apoptosis. ROS can be produced intracellularly, from immature sperm, oocytes, and embryos. Additionally, several external factors may induce high ROS production in the ART setup, including atmospheric oxygen, CO2 incubators, consumables, visible light, temperature, humidity, volatile organic compounds, and culture media additives. Pathological amounts of ROS can also be generated during the cryopreservation-thawing process of gametes or embryos. Generally, these factors can act at any stage during ART, from gamete preparation to embryo development, till the blastocyst stage. In this review, we discuss the in vitro conditions and environmental factors responsible for the induction of OS in an ART setting. In addition, we describe the effects of OS on gametes and embryos. Furthermore, we highlight strategies to ameliorate the impact of OS during the whole human embryo culture period, from gametes to blastocyst stage.