Intracytoplasmic morphologically selected sperm injection (IMSI) does not improve outcome in patients with two successive IVF-ICSI failures

Application of Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) on a Teratozoospermic Patient and Its Effect on the In-Vitro Fertilization (IVF) Outcome

Infertility, defined as the inability to conceive after 12 months of unprotected sexual activity, affects millions globally. Approximately 80% of cases have identifiable causes, including endometriosis, tubal obstruction, ovulatory dysfunction, and male sperm abnormalities. Lifestyle factors, such as smoking and obesity, also impact fertility. Sperm morphology, a key factor in male infertility, often presents as teratozoospermia, with defects in the head, midpiece, or tail. Poor ovarian reserve, indicated by low anti-mullerine hormone (AMH) and antra-follicular count (AFC) values, contributes to female infertility, often exacerbated by age-related factors. Elevated follicle-stimulating hormone (FSH) levels further diminish oocyte quantity and quality. Intracytoplasmic Sperm Injection (ICSI), a micromanipulation technique aiding infertile couples, may face challenges in detecting subtle sperm morphology defects. Advanced methods like Motile Sperm Organelle Morphological Examination (MSOME) and Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) under high magnification enhance sperm selection accuracy. We present the case of a 36-year-old woman and her 42-year-old husband who sought assistance after seven years of infertility. Previous Intrauterine injection (IUI) and ICSI attempts failed due to the wife's low ovarian reserve and elevated FSH, compounded by the husband's teratozoospermia. Their earlier In-Vitro Fertilization (IVF) experience yielded a single poor-quality oocyte, hindering blastocyst formation. Investigations revealed the wife's poor AFC, AMH of 0.033ng/ml, and FSH at 24IU/L. Her medical history included hypertension and gallbladder removal. The husband exhibited 98% defective sperm, devoid of a substance abuse history. The wife's family had a polycystic ovarian syndrome (PCOS) history, and her low AMH and AFC yielded only three poor-quality oocytes during the current assessment. Oocytes were retrieved, and sperm were selected with the help of IMSI. After ICSI, the patient successfully conceived.

Translational Nanomedicines Across Human Reproductive Organs Modeling on Microfluidic Chips: State-of-the-Art and Future Prospects

Forecasting the consequence of nanoparticles (NPs) and therapeutically significant molecules before materializing for human clinical trials is a mainstay for drug delivery and screening processes. One of the noteworthy obstacles that has prevented the clinical translation of NP-based drug delivery systems and novel drugs is the lack of effective preclinical platforms. As a revolutionary technology, the organ-on-a-chip (OOC), a coalition of microfluidics and tissue engineering, has surfaced as an alternative to orthodox screening platforms. OOC technology recapitulates the structural and physiological features of human organs along with intercommunications between tissues on a chip. The current review discusses the concept of microfluidics and confers cutting-edge fabrication processes for chip designing. We also outlined the advantages of microfluidics in analyzing NPs in terms of characterization, transport, and degradation in biological systems. The review further elaborates the scope and research on translational nanomedicines in human reproductive organs (testis, placenta, uterus, and menstrual cycle) by taking the advantages offered by microfluidics and shedding light on their potential future implications. Finally, we accentuate the existing challenges for clinical translation and scale-up dynamics for microfluidics chips and emphasize its future perspectives.

Advanced Sperm Selection Strategies as a Treatment for Infertile Couples: A Systematic Review

Assisted reproductive technology (ART) is an essential tool to overcome infertility, and is a worldwide disease that affects millions of couples at reproductive age. Sperm selection is a crucial step in ART treatment, as it ensures the use of the highest quality sperm for fertilization, thus increasing the chances of a positive outcome. In recent years, advanced sperm selection strategies for ART have been developed with the aim of mimicking the physiological sperm selection that occurs in the female genital tract. This systematic review sought to evaluate whether advanced sperm selection techniques could improve ART outcomes and sperm quality/functionality parameters compared to traditional sperm selection methods (swim-up or density gradients) in infertile couples. According to preferred reporting items for systematic reviews and meta-analyses (PRISMA guidelines), the inclusion and exclusion criteria were defined in a PICOS (population, intervention, comparator, outcome, study) table. A systematic search of the available literature published in MEDLINE-PubMed until December 2021 was subsequently conducted. Although 4237 articles were recorded after an initial search, only 47 studies were finally included. Most reports (30/47; 63.8%) revealed an improvement in ART outcomes after conducting advanced vs. traditional sperm selection methods. Among those that also assessed sperm quality/functionality parameters (12/47), there was a consensus (10/12; 83.3%) about the beneficial effect of advanced sperm selection methods on these variables. In conclusion, the application of advanced sperm selection methods improves ART outcomes. In spite of this, as no differences in the reproductive efficiency between advanced methods has been reported, none can be pointed out as a gold standard to be conducted routinely. Further research addressing whether the efficiency of each method relies on the etiology of infertility is warranted.

IMSI—Guidelines for Sperm Quality Assessment

Intracytoplasmic sperm injection (ICSI) is a widely used and accepted treatment of choice for oocyte fertilization. However, the quality of sperm selection depends on the accurate visualization of the morphology, which can be achieved with a high image resolution. We aim to correct the conviction, shown in a myriad of publications, that an ultra-high magnification in the range of 6000×–10,000× can be achieved with an optical microscope. The goal of observing sperm under the microscope is not to simply get a larger image, but rather to obtain more detail—therefore, we indicate that the optical system’s resolution is what should be primarily considered. We provide specific microscope system setup recommendations sufficient for most clinical cases that are based on our experience showing that the optical resolution of 0.5 μm allows appropriate visualization of sperm defects. Last but not least, we suggest that mixed research results regarding the clinical value of IMSI, comparing to ICSI, can stem from a lack of standardization of microscopy techniques used for both ICSI and IMSI.

An Open Prospective Study on Whether Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) Offers a Better Outcome Than Conventional Intracytoplasmic Sperm Injection (ICSI)

Objective

To differentiate the in vitro fertilization (IVF) outcomes between the two procedures, intracytoplasmic morphologically selected sperm injection (IMSI) and intracytoplasmic sperm injection (ICSI) in terms of relation to chemical pregnancy percentage, clinical pregnancy, live birth, miscarriage, and fertilization rates, respectively.

Patients and methods

This Open Prospective clinical trial was conducted during the period between Jan 2016 and Dec 2017 at one IVF unit. A total of 446 ICSI cycles and 79 IMSI cycles were conducted. Females were divided into four subgroups according to age.

Results

The study involved 525 couples (446 first trial ICSI cycles) and (79 first trial IMSI cycles). ICSI was statistically better than the IMSI in relation to the chemical pregnancy, clinical pregnancy (CPR), live birth (LBR), and fertilization rates, respectively (p < 0.05). However, there were no statistically significant differences between the ICSI and IMSI in relation to the miscarriage rate. There were statistically significant differences favoring ICSI in all subgroups except 35-37, in relation to chemical pregnancy; and in the 38-40 and >40 subgroups in relation to CPR. There were no statistically significant differences in these subgroups regarding the live birth, miscarriage, or fertilization rates.

Conclusions

This study showed that IMSI is not superior to conventional ICSI at the first attempt. Based on the findings in this study, we would not advise couples to choose IMSI at their first treatment attempt.

Impact of Intracytoplasmic Morphologically Selected Sperm Injection (IMSI) on Birth Defects: A Systematic Review and Meta-Analysis

OBJECTIVE

It is generally accepted that the incidence of birth defects in spontaneously conceived children ranges between 2.0-4.0%. However, several studies have shown that babies born after assisted reproductive technology (ART) procedures tend to present more congenital malformations than naturally conceived children, with 6.5% of the children born after intracytoplasmic sperm injection (ICSI) presenting birth defects. The use of high magnification sperm selection before ICSI was introduced in the early 2000s to allow the identification of spermatozoa with low risk of sperm DNA damage. Intracytoplasmic morphologically selected sperm injection (IMSI) is expected to change the incidence of congenital malformations, although data on the incidence of birth defects in children conceived after IMSI are still scarce.

METHODS

A systematic review based on searches performed in electronic databases (PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane Central Register of Controlled Trials) including articles published by February 2021 was conducted to identify trials comparing the neonatal outcomes of ICSI and IMSI. The outcome measured was the rate of birth defects in children born after ICSI or IMSI. Three trials were included as targets for data extraction and meta-analysis.

RESULTS

Our meta-analysis included 3907 children conceived after IMSI (1280) or ICSI (2627). The incidence of birth defects was statistically different, with 2.5% (32/1280) in IMSI and 4.5% (119/2627) in ICSI (RR=0.59; 95% CI=0.40-0.87; p=0.007). The results demonstrated that IMSI decreased the incidence of structural defects compared to ICSI - 2.2% (18/830) vs. 3.8% (78/2049) - in a statistically significant manner (RR=0.58; 95%CI=0.35-0.96; p=0.04). No significant difference was observed in chromosomal abnormalities (Trisomy 13; 18; 21 and Triple X) between children conceived after IMSI (8/830) or ICSI (19/2049) (RR=1.07; 95%CI=0.47-2.43; p=0.87).

CONCLUSIONS

IMSI seems to be an effective tool at reducing the incidence of structural defects compared to ICSI. However, IMSI does not change the incidence of chromosomal abnormalities.

Semantic segmentation of human oocyte images using deep neural networks

BACKGROUND

Infertility is a significant problem of humanity. In vitro fertilisation is one of the most effective and frequently applied ART methods. The effectiveness IVF depends on the assessment and selection of gametes and embryo with the highest developmental potential. The subjective nature of morphological assessment of oocytes and embryos is still one of the main reasons for seeking effective and objective methods for assessing quality in automatic manner. The most promising methods to automatic classification of oocytes and embryos are based on image analysis aided by machine learning techniques. The special attention is paid on deep neural networks that can be used as classifiers solving the problem of automatic assessment of the oocytes/embryos.

METHODS

This paper deals with semantic segmentation of human oocyte images using deep neural networks in order to develop new version of the predefined neural networks. Deep semantic oocyte segmentation networks can be seen as medically oriented predefined networks understanding the content of the image. The research presented in the paper is focused on the performance comparison of different types of convolutional neural networks for semantic oocyte segmentation. In the case study, the merits and limitations of the selected deep neural networks are analysed.

RESULTS

71 deep neural models were analysed. The best score was obtained for one of the variants of DeepLab-v3-ResNet-18 model, when the training accuracy (Acc) reached about 85% for training patterns and 79% for validation ones. The weighted intersection over union (wIoU) and global accuracy (gAcc) for test patterns were calculated, as well. The obtained values of these quality measures were 0,897 and 0.93, respectively.

CONCLUSION

The obtained results prove that the proposed approach can be applied to create deep neural models for semantic oocyte segmentation with the high accuracy guaranteeing their usage as the predefined networks in other tasks.

The impact of cryopreservation on the morphology of spermatozoa in men with oligoasthenoteratozoospermia

The cryopreservation of ejaculate can reduce the viability, motility, and morphological characteristics of the spermatozoa of infertile men. Oligoasthenoteratozoospermia (OAT) is the most common cause of male subfertility. The aim of this study was to evaluate the morphological characteristics and viability of progressive motile sperm fraction before and after cryopreservation, and to determine whether cryopreservation of progressive motile sperm fraction is effective in eliminating morphologically abnormal sperm in men with OAT. An increased proportion of spermatozoa with normal morphology in fresh progressive motile sperm fraction compared with fresh ejaculate has been observed. After cryopreservation, the motility was 65.5 ± 8.8%; the proportion of spermatozoa with normal morphology increased non-significantly compared with freshly prepared motile sperm fraction (35.6 ± 5.5%). Concurrently, the proportion of cryopreserved spermatozoa with head defects increased significantly by 1.7 times (to 38.4 ± 4.7%) and the proportion of almost all morphologically abnormal sperm cells, particularly spermatozoa with multiple abnormalities, was reduced significantly. These data appear to be a novel finding in the context of patients with OAT. Using such spermatozoa for in vitro fertilization leads to a significant decrease in both a number of embryos at the cleavage stage and the blastocysts formation rate. High-magnification sperm morphology examination and selection, IMSI, post-cryopreservation significantly increased the likelihood of successful oocyte fertilization and subsequent embryo development.

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

Association between early embryo morphokinetics plus transcript levels of sperm apoptotic genes and clinical outcomes in IMSI and ICSI cycles of male factor patients

PURPOSE

The aim was to assess the correlation of sperm apoptotic transcript levels with cleavage stage embryokinetic and pregnancy outcomes of intracytoplasmic morphologically selected sperm injection (IMSI) and ICSI methods in patients with male factor infertility.

MATERIAL AND METHODS

Eighty male factor cases were divided into ICSI and IMSI groups. ICSI was done routinely, and for IMSI, sperm was selected at high magnification and injected. On day 3, time-lapse parameters were evaluated, and the best embryos were transferred and followed to delivery. In addition, sperm DNA fragmentation and apoptotic transcript levels were quantified using reverse transcription Q-PCR between the groups.

RESULTS

IMSI selected spermatozoa had lower DNA fragmentation and apoptotic transcript levels compared with ICSI (p < 0.0001). Moreover, all cytokinetic variables and cleavage abnormalities were noticeably different between groups (p < 0.0001); the rates of clinical outcomes were higher in the IMSI group. The transcript levels of Caspase 3 showed a moderate negative correlation with s2 and s3 (rs = - 0.57, P = 0.008 and rs = - 0.51, p = 0.021, respectively) in the IMSI group. However, there was no relationship between sperm apoptotic transcript levels and clinical outcomes in two groups.

CONCLUSIONS

Sperms selected at high magnification showed lower DNA fragmentation and apoptosis genes transcript. Also, better embryo kinetics and clinical outcomes were confirmed in IMSI than ICSI groups. Some time-lapse parameters may be associated with transcript levels of apoptosis genes. Therefore, these noninvasive techniques may be unique in assisting couples with male factor infertility.

TRIAL REGISTRATION

This trial retrospectively registered on 4 July 2020 (IRCT20180130038561N1).

Regular (ICSI) versus ultra-high magnification (IMSI) sperm selection for assisted reproduction

BACKGROUND

Subfertility is a condition found in up to 15% of couples of reproductive age. Gamete micromanipulation, such as intracytoplasmic sperm injection (ICSI), is very useful for treating couples with compromised sperm parameters. An alternative method of sperm selection has been described; the spermatozoa are selected under high magnification (over 6000x) and used for ICSI. This technique, named intracytoplasmic morphologically selected sperm injection (IMSI), has a theoretical potential to improve reproductive outcomes among couples undergoing assisted reproduction techniques (ART). However, our previous version of this Cochrane Review was unable to find evidence that supported this possible beneficial effect. This is an update of Teixeira 2013.

OBJECTIVES

To identify, appraise, and summarise the available evidence regarding efficacy and safety of IMSI compared to ICSI in couples undergoing ART.

SEARCH METHODS

We searched for randomised controlled trials (RCTs) in these electronic databases: the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, LILACS, and in these trial registers: ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform. We also handsearched the reference lists of included studies and similar reviews. We performed the last electronic search on 18 November 2019.

SELECTION CRITERIA

We only considered RCTs that compared ICSI and IMSI; we did not include quasi-randomised trials. We considered studies that permitted the inclusion of the same participant more than once (cross-over or per cycle trials) only if data regarding the first treatment of each participant were available.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, data extraction, and assessment of the risk of bias and quality of the evidence; we solved disagreements by consulting a third review author. We corresponded with study investigators to resolve any queries, as required.

MAIN RESULTS

The updated search retrieved 535 records; we included 13 parallel-designed RCTs comparing IMSI and ICSI (four studies were added since the previous version), comprising 2775 couples (IMSI = 1256; ICSI = 1519). We are uncertain if IMSI improves live birth rates (risk ratio (RR) 1.11, 95% confidence interval (CI) 0.89 to 1.39; 5 studies, 929 couples; I² = 1%), miscarriage rates per couple (RR 1.07, 95% CI 0.78 to 1.48; 10 studies, 2297 couples; I² = 0%, very-low quality evidence), and miscarriage rate per pregnancy (RR 0.90, 95% CI 0.68 to 1.20; 10 studies, 783 couples; I² = 0%, very-low quality evidence). We are uncertain if IMSI improves clinical pregnancy rates (RR 1.23, 95% CI 1.11 to 1.37; 13 studies, 2775 couples; I² = 47%, very-low quality evidence). None of the included studies reported congenital abnormalities. We judged the evidence for all outcomes to be of very low-quality. We downgraded the quality of the evidence due to limitations of the included studies (risk of bias), inconsistency of results, and a strong indication of publication bias.

AUTHORS' CONCLUSIONS

The current evidence from randomised controlled trials does not support or refute the clinical use of intracytoplasmic sperm injection (intracytoplasmic morphologically selected sperm injection (IMSI). We are very uncertain of the chances of having a live birth and of the risk of having a miscarriage. We found very low-quality evidence that IMSI may increase chances of a clinical pregnancy, which means that we are still very uncertain about any real difference. We did not find any trials reporting on the risk of congenital abnormalities. Well-designed and sufficiently powered trials are still required.

The Beneficial Role of Intra Cytoplasmic Morphologically Selected Sperm Injection (IMSI) in Assisted Reproduction

Since the introduction of intracytoplasmic sperm injection (ICSI), the importance of sperm morphology assessment has been given attention in the assisted reproduction field. It is important to select a good-quality motile spermatozoon for giving a better embryo quality in assisted reproduction technique (ART). In ICSI, sperm morphology evaluation is limited due to its low magnification. However, by using intracytoplasmic morphologically selected sperm injection (IMSI), the selection is done at high magnification of ×6600 using motile sperm organelle morphology examination (MSOME). Therefore, it becomes possible to select a good quality spermatozoon with an intact nucleus that may enhance the pregnancy outcomes. Although all patients can benefit from IMSI, it is important to standardize which techniques (IMSI or ICSI) could be used or which group of patients benefit from IMSI to maximize the efficiency of this advanced technology.

Novel Techniques of Sperm Selection for Improving IVF and ICSI Outcomes

Almost 50% of the infertility cases are due to male factors. Assisted reproductive technologies (ARTs) allow to overcome the incapacity of these patients' spermatozoa to fertilize the oocyte and produce a viable and healthy offspring, but the efficiency of the different techniques has still the potential to improve. According to the latest reports of the European Society of Human Reproduction and Embryology (ESHRE) and the Centers for Disease Control and Prevention of the United States (CDC), the percentages of deliveries per ART cycle in 2014 and 2016 were 21 and 22%, respectively. Among the reasons for this relatively low efficiency, the quality of the spermatozoa has been pointed out as critical, and the presence of high percentages of DNA-damaged spermatozoa in patients' ejaculates is possibly one of the main factors reducing the ARTs outcomes. Thus, one of the main challenges in reproductive medicine is to ensure the highest quality of the spermatozoa used in ARTs, and specifically, in terms of genetic integrity. The latest techniques for the preparation and selection of human spermatozoa are herein discussed focusing on those proven to improve one or several of the following parameters: sperm genetic integrity, fertilization capacity, embryo production, and in vitro survival, as well as pregnancy and delivery rates following in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). In addition, we discuss the potential of techniques developed in non-human mammals that could be further transferred to the clinic.

Live birth and miscarriage rate following intracytoplasmic morphologically selected sperm injection vs intracytoplasmic sperm injection: An updated systematic review and meta-analysis

INTRODUCTION

Intracytoplasmic morphologically selected sperm injection (IMSI) is one of the sperm selection techniques used for assisted reproduction which has been applied for a variety of indications including previously failed fertilization with intracytoplasmic sperm injection (ICSI). A Cochrane review¹ found no difference in outcomes between either modality of sperm selection. Since the Cochrane review was published there have been a further two randomized controlled trials comparing IMSI and ICSI. This systematic review and meta-analysis aims to compare IMSI with ICSI as insemination methods regarding live birth rate and miscarriage rate.

MATERIAL AND METHODS

Systematic review of randomized controlled trials, observational studies and similar reviews in electronic databases published before January 2018.

RESULTS

We found nine randomized controlled trials, evaluating 1610 cycles of in vitro fertilization and 15 observational studies evaluating 1243 cycles of in vitro fertilization. Meta-analysis of the included randomized controlled trials showed no difference in the live birth rate or miscarriage rate between the ICSI and IMSI groups. Meta-analysis of five observational studies showed a significantly higher number of live births in the IMSI group than ICSI group (live birth rate odds ratio 1.47, 95% confidence interval 1.16-4.07), with a moderate degree of heterogeneity (I²  = 41%). Additionally, from six observational studies, a significantly lower miscarriage rate was observed in the IMSI group than in the ICSI group (odds ratio 0.51, 95% confidence interval 0.37-0.70, I²  = 0%).

CONCLUSIONS

Meta-analysis of randomized studies comparing IMSI to ICSI has not shown any difference in live birth rate and miscarriage rate. Meta-analysis of observational studies, which must be interpreted with caution, revealed an increased live birth rate and decreased miscarriage rate with IMSI vs ICSI.

Male Infertility Problem: A Contemporary Review on Present Status and Future Perspective

Semen quality plays a pivotal role in maintaining healthy fertilizing ability of spermatozoa. Male infertility is a rising global problem with an increasing declining in male semen quality among men living in Africa, Europe, North American, and Asia. Though the sperm acquire proactive mechanisms during spermatogenesis and their epididymal maturation, they still remain viable for toxic insult. Declining semen quality is a major contributor to infertility. Studies have postulated that different factors, such as exposure to pesticides, industrial chemicals, heavy metals, obesity, alcoholism, tobacco smoking, sedentary lifestyles, poor nutrient intake, oxidative stress, physiological factors, genetic factors can influence male fertility. Routine semen analysis and assays for sperm chromatin integrity are the most widely utilized and best studied adjunctive diagnostics in male infertility. Over the years, scientists have developed different treatment options for male infertility. Male infertility with known etiology can be treated successfully, but other causes like genetic factors require pragmatic approaches. This article summarizes protective mechanisms of spermatogenesis, causes, diagnosis, and both modern and traditional treatment approaches of male infertility. Further, this article highlights present issues and direction for future exploration of the male infertility problem.

Magnetic-activated cell sorting of non-apoptotic spermatozoa improves the quality of embryos according to female age: a prospective sibling oocyte study

PURPOSE

The main aim of our study was to evaluate the benefit of the use of non-apoptotic spermatozoa selected by magnetic-activated cell sorting (MACS) for ICSI procedures for couples in which the women had good prognoses and the male factor of infertility was teratozoospermia.

METHODS

Twenty-six couples were treated with ICSI after MACS selection of non-apoptotic spermatozoa following a sibling oocyte approach. Half of the oocytes were microinjected with conventionally prepared spermatozoa, and the other half were microinjected with non-apoptotic, MACS-selected spermatozoa. To assess the influence of MACS selection of spermatozoa on the outcomes of the ICSI cycles, the fertilization, embryo quality, pregnancy, and delivery rates were evaluated and compared between the sibling oocyte groups.

RESULTS

When subpopulations of couples according to female age were analyzed, a significant difference in quality of blastocyst was observed. More precisely, in a group that was treated with MACS-ICSI, a higher percentage of good quality blastocysts was found among women older than 30 years (75.0 vs. 33.3%; P = 0.028), while there was no difference among younger women. If all included couples were compared regardless of age, no significant difference was observed in the outcome of the ICSI/MACS-ICSI cycles in terms of oocytes and embryos. Additionally, after the ICSI and MACS-ICSI procedures, the morphologies of the prepared spermatozoa were compared. Results showed that the overall percentage of morphologically normal spermatozoa did not differ significantly between the ICSI and MACS-ICSI procedures. However, detailed analyses of the morphologically abnormal spermatozoa revealed significantly more spermatozoa with abnormal tails after MACS-ICSI procedure, which may be potential consequence of the selection procedure. Moreover, the trends towards less spermatozoa with abnormal heads and towards more spermatozoa with abnormal necks and midpieces after MACS-ICSI procedure were revealed, although the differences were not significant.

CONCLUSIONS

Couples dealing with male infertility due to teratozoospermia can benefit from MACS selection of spermatozoa with higher percentage of good quality blastocysts but only when the woman is older than 30 years.

Intracytoplasmic sperm injection: state of the art in humans

Among infertile couples, 25% involve both male and female factors, while male factor alone accounts for another 25% due to oligo-, astheno-, teratozoospermia, a combination of the three, or even a complete absence of sperm cells in the ejaculate and can lead to a poor prognosis even with the help of assisted reproductive technology (ART). Intracytoplasmic sperm injection (ICSI) has been with us now for a quarter of a century and in spite of the controversy generated since its inception, it remains in the forefront of the techniques utilized in ART. The development of ICSI in 1992 has drastically decreased the impact of male factor, resulting in millions of pregnancies worldwide for couples who, without ICSI, would have had little chance of having their own biological child. This review focuses on the state of the art of ICSI regarding utility of bioassays that evaluate male factor infertility beyond the standard semen analysis and describes the current application and advances in regard to ICSI, particularly the genetic and epigenetic characteristics of spermatozoa and their impact on reproductive outcome.

Strategies to improve fertilisation rates with assisted conception: a systematic review

Successful fertilisation is one of the key steps determining success of assisted conception. Various factors including sperm or oocyte pathology and environmental factors have a significant impact on fertilisation rates. This systematic review is aimed to evaluate the existing evidence about factors affecting fertilisation and strategies to improve fertilisation rates. A literature search was performed using Ovid MEDLINE ® (Jan 1950-April 2016), EMBASE (Jan 1950-April 2016), Ovid OLDMEDLINE ®, Pre-MEDLINE (Jan 1950-April 2016) and the Cochrane Library. Relevant key words were used to combine sets of results and a total 243 papers were screened. Only qualitative analysis was performed, as there was major heterogeneity in study design and methodology for quantitative synthesis. Factors affecting fertilisation were divided into sperm- and oocyte-related factors. The methods to improve fertilisation rates were grouped together based on the approach used to improve fertilisation rates. Optimising laboratory condition and procedural effects in techniques is associated with improved fertilisation rates. Various techniques are described to improve fertilisation rates including assisted oocyte activation, physiological intracytoplasmic sperm injection (PICSI) and intracytoplasmic morphologically selected sperm injection (IMSI). This review highlights the promising strategies under research to enhance fertilisation rates. Adequately powered multicentre randomised trials are required to evaluate these techniques before considering clinical application.

Are there optimal numbers of oocytes, spermatozoa and embryos in assisted reproduction?

The aim of this overview is to discuss the current information about the search for the optimum yield of gametes in assisted reproduction, as one of the major pillars of IVF success. The first topic is focused on the number of male gametes and the possible impact of some genetic traits on these parameters. The number of spermatozoa did not seem to be crucial when there is no severe male factor of infertility. Genetic testing prior to using those sperm cells is very important. Different methods were applied in order to elect the "best" spermatozoa according to specific indications. The next problem discussed is the importance of the number of oocytes collected. Several studies have agreed that "15 oocytes is the perfect number," as the number of mature oocytes is more important. However, if elective single embryo transfer is performed, the optimal number of oocytes will enable a proper embryo selection. The third problem discussed concerns fertility preservation. Many educational programs promote and encourage procreation at maternal ages between 20-35 years, since assisted reproduction is unable to fully overcome the effects of female aging and fertility loss after that age. It is also strongly recommended to ensure a reasonable number of cryopreserved mature oocytes, preferably in younger ages (<35), for which an average of two stimulation cycles are likely required. For embryo cryopreservation, the "freeze all" strategy suggests the vitrification of good embryos, therefore quality is prior to number and patient recruitment for this strategy should be performed cautiously.