The IMSI procedure improves poor embryo development in the same infertile couples with poor semen quality: a comparative prospective randomized study

The mammalian sperm factor phospholipase C zeta is critical for early embryo division and pregnancy in humans and mice

STUDY QUESTION

Are sperm phospholipase C zeta (PLCζ) profiles linked to the quality of embryogenesis and pregnancy?

SUMMARY ANSWER

Sperm PLCζ levels in both mouse and humans correlate with measures of ideal embryogenesis whereby minimal levels seem to be required to result in successful pregnancy.

WHAT IS KNOWN ALREADY

While causative factors underlying male infertility are multivariable, cases are increasingly associated with the efficacy of oocyte activation, which in mammals occurs in response to specific profiles of calcium (Ca2+) oscillations driven by sperm-specific PLCζ. Although sperm PLCζ abrogation is extensively linked with human male infertility where oocyte activation is deficient, less is clear as to whether sperm PLCζ levels or localization underlies cases of defective embryogenesis and failed pregnancy following fertility treatment.

STUDY DESIGN, SIZE, DURATION

A cohort of 54 couples undergoing fertility treatment were recruited at the assisted reproductive technology laboratory at the King Faisal Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia. The recruitment criteria for males was a minimum sperm concentration of 5×106 sperm/ml, while all female patients had to have at least five oocytes. Sperm PLCζ analysis was performed in research laboratories, while semen assessments were performed, and time-lapse morphokinetic data were obtained, in the fertility clinic as part of routine treatment. The CRISPR/Cas9 system was concurrently used to induce indels and single-nucleotide mutations within the Plcζ gene to generate strains of Plcζ mutant mice. Sperm PLCζ was evaluated using immunofluorescence and immunoblotting with an antibody of confirmed consistent specificity against PLCζ.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We evaluated PLCζ profiles in sperm samples from 54 human couples undergoing fertility treatment in the context of time-lapse morphokinetic analysis of resultant embryos, correlating such profiles to pregnancy status. Concurrently, we generated two strains of mutant Plcζ mice using CRISPR/Cas9, and performed IVF with wild type (WT) oocytes and using WT or mutant Plcζ sperm to generate embryos. We also assessed PLCζ status in WT and mutant mice sperm in the context of time-lapse morphokinetic analysis and breeding outcomes.

MAIN RESULTS AND THE ROLE OF CHANCE

A significant (P ≤ 0.05) positive relationship was observed between both PLCζ relative fluorescence and relative density with the times taken for both the second cell division (CC2) (r = 0.26 and r = 0.43, respectively) and the third cell division (S2) (r = 0.26). Examination of localization patterns also indicated significant correlations between the presence or absence of sperm PLCζ and CC2 (r = 0.27 and r = -0.27, respectively; P ≤ 0.025). Human sperm PLCζ levels were at their highest in the ideal times of CC2 (8-12 h) compared to time ranges outside the ideal timeframe (<8 and >12 h) where levels of human sperm PLCζ were lower. Following assignment of PLCζ level thresholds, quantification revealed a significantly higher (P ≤ 0.05) rate of successful pregnancy in values larger than the assigned cut-off for both relative fluorescence (19% vs 40%, respectively) and relative density (8% vs 54%, respectively). Immunoblotting indicated a single band for PLCζ at 74 kDa in sperm from WT mice, while a single band was also observed in sperm from heterozygous of Plcζ mutant mouse sperm, but at a diminished intensity. Immunofluorescent analysis indicated the previously reported (Kashir et al., 2021) fluorescence patterns in WT sperm, while sperm from Plcζ mutant mice exhibited a significantly diminished and dispersed pattern at the acrosomal region of the sperm head. Breeding experiments indicated a significantly reduced litter size of mutant Plcζ male mice compared to WT mice, while IVF-generated embryos using sperm from mutant Plcζ mice exhibited high rates of polyspermy, and resulted in significantly reduced numbers of these embryos reaching developmental milestones.

LIMITATIONS, REASONS FOR CAUTION

The human population examined was relatively small, and should be expanded to examine a larger multi-centre cohort. Infertility conditions are often multivariable, and it was not possible to evaluate all these in human patients. However, our mutant Plcζ mouse experiments do suggest that PLCζ plays a significant role in early embryo development.

WIDER IMPLICATIONS OF THE FINDINGS

We found that minimal levels of PLCζ within a specific range were required for optimal early embryogenesis, correlating with increased pregnancy. Levels of sperm PLCζ below specific thresholds were associated with ineffective embryogenesis and lower pregnancy rates, despite eliciting successful fertilization in both mice and humans. To our knowledge, this represents the first time that PLCζ levels in sperm have been correlated to prognostic measures of embryogenic efficacy and pregnancy rates in humans. Our data suggest for the first time that the clinical utilization of PLCζ may stand to benefit not just a specific population of male infertility where oocyte activation is completely deficient (wherein PLCζ is completely defective/abrogated), but also perhaps the larger population of couples seeking fertility treatment.

STUDY FUNDING/COMPETING INTEREST(S)

J.K. is supported by a faculty start up grant awarded by Khalifa University (FSU-2023-015). This study was also supported by a Healthcare Research Fellowship Award (HF-14-16) from Health and Care Research Wales (HCRW) to J.K., alongside a National Science, Technology, and Innovation plan (NSTIP) project grant (15-MED4186-20) awarded by the King Abdulaziz City for Science and Technology (KACST) for J.K. and A.M.A. The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

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.

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.

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.

Sperm DNA fragmentation on the day of fertilisation is not associated with assisted reproductive technique outcome independently of gamete quality

The evaluation of sperm DNA fragmentation has been postulated as a predictive molecular parameter of the semen fertilising potential, as well as the ability to give rise to a healthy embryo and an ongoing pregnancy. However, there are controversial results due to oocyte quality, the use of different measurement techniques and interpretation criteria. Our objective is to investigate if sperm DNA fragmentation on the day of fertilisation influences in vitro fertilisation (IVF) outcome in a prospective double-blind study. Three groups of patients were defined: (i) 68 couples undergoing intracytoplasmic sperm injection (ICSI) due to severe male factor with normal ovarian response (NOR); (ii) 113 couples undergoing conventional in vitro fertilisation (IVF) in our oocyte donation programme due to ovarian failure; and (iii) 150 low ovarian response (LOR) patients undergoing ICSI or IVF. TUNEL assay was performed from an aliquot of each capacitated semen sample to detect DNA fragmentation. There was no relationship between blood serum β-hCG positive test, clinical pregnancy and first trimester miscarriage with DFI levels in NOR (p = 0.41, p = 0.36, p = 0.40), recipient (p = 0.49, p = 0.99 and p = 0.38) and LOR (p = 0.52, p = 0.20, p = 0.64) groups of patients, respectively. Therefore, ART outcomes are not affected by sperm DNA fragmentation independently of gamete quality.

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 BlastGen study: a randomized controlled trial of blastocyst media supplemented with granulocyte-macrophage colony-stimulating factor

RESEARCH QUESTION

Does Embryogen®/BlastGen™ culture medium improve live birth rates compared with standard culture medium for women undergoing IVF and intracytoplasmic sperm injection (ICSI) with poor prognosis.

DESIGN

Randomized clinical trial. A total of 100 couples undergoing IVF/ICSI were randomly allocated to having their inseminated oocytes incubated in either Embryogen®/BlastGen™ sequential culture media or standard Cleavage/Blastocyst sequential culture media for 5 days (ClinicalTrials.gov Identifier: NCT02305420).

RESULTS

No statistically significant difference in live birth rate was found between the control group and the Embryogen®/BlastGen™ group (17 [34%] versus 11 [22%], respectively) (OR 0.55; 95% CI 0.22 to 1.32; P = 0.18). After adjustment for maternal age, body mass index and fertilization procedure, the blastulation rate reduced (40.6 ± 26.5 versus 24.6 ± 26.7; RR 0.70, CI 0.52 to 0.95; P < 0.05), and grade of the embryo transferred (OR 0.35, CI 0.16 to 0.77; P < 0.01) when Embryogen®/BlastGen™ medium was used.

CONCLUSION

A significant reduction in day-5 embryo outcome parameters was found using Embryogen®/BlastGen™ compared with standard medium, and insufficient evidence of a difference in pregnancy outcomes. Taking into consideration the small samples size, study limitations and strict inclusion criteria of this single-centre study, further research is needed to determine the efficacy of Embryogen®/BlastGen™ medium in couples undergoing IVF/ICSI.

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.

Intracytoplasmic sperm injection for male infertility and consequences for offspring

Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

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.

Intracytoplasmic morphologically selected sperm injection, but for whom?

Intracytoplasmic sperm injection (ICSI) is performed in cases of infertility by injecting a motile and morphologically normal sperm cell under a routine ×400 magnification at which is hard to distinguish morphologically healthy sperm. Recently, the use of high-powered differential interference contrast optics gave the opportunity to select a sperm under ultra-high magnification of ×10,160. The aim of the present study was to evaluate the efficacy of the intracytoplasmic morphologically selected sperm injection (IMSI) technique in different infertility populations undergoing ICSI. Main outcome measures of routine ICSI were compared with IMSI in three different groups of patients (1, non-selected; 2, male infertility; and 3, repeated implantation failure group). Results were analysed to evaluate the effects of the IMSI procedure and to find the most suitable group of patients who may benefit from the procedure. IMSI caused a significant increase in the fertilization and top quality embryo rates in the male infertility group and a significant increase in fertilization and pregnancy rates in the repeated implantation failure group, whereas no effect was observed in the non-selected group with patients of various indications. A positive effect of IMSI on the outcome of male factor infertility and repeated implantation failure patients was observed. Data observed confirmed that the application of IMSI was beneficial for a selected group of patients with male factor infertility and repeated implantation failure.

Advanced sperm selection techniques for assisted reproduction

BACKGROUND

Assisted reproductive technologies (ART) including in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI), combine gametes to enhance the probability of fertilisation and pregnancy. Advanced sperm selection techniques are increasingly employed in ART, most commonly in cycles utilising ICSI. Advanced sperm selection techniques are proposed to improve the chance that structurally intact and mature sperm with high DNA integrity are selected for fertilisation. Strategies include selection according to surface charge; sperm apoptosis; sperm birefringence; ability to bind to hyaluronic acid; and sperm morphology under ultra-high magnification. These techniques are intended to improve ART outcomes.

OBJECTIVES

To evaluate the effectiveness and safety of advanced sperm selection techniques on ART outcomes.

SEARCH METHODS

We conducted a systematic search of electronic databases (Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL via the Cochrane Register of Studies Online, MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL); trials registers (ClinicalTrials.gov, Current Controlled Trials, and the World Health Organization International Clinical Trials Registry Platform); conference abstracts (Web of Knowledge); and grey literature (OpenGrey) for relevant randomised controlled trials (RCTs). We handsearched the reference lists of included studies and similar reviews. The search was conducted in June 2018.

SELECTION CRITERIA

We included RCTs comparing advanced sperm selection techniques versus standard IVF, ICSI, or another technique. We excluded studies of intracytoplasmic morphologically selected sperm injection (IMSI), as they are subject to a separate Cochrane Review. Primary outcomes measured were live birth and miscarriage per woman randomly assigned. Secondary outcome measures included clinical pregnancy per woman randomly assigned. Secondary adverse events measured included miscarriage per clinical pregnancy and foetal abnormality.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility and risk of bias and extracted data. Any disagreements were resolved by consultation with a third review author. We consulted study investigators to resolve queries. Risk ratios (RRs) were calculated with 95% confidence intervals (CIs). We combined studies using a fixed-effect model. We evaluated the quality of the evidence using GRADE methods.

MAIN RESULTS

We included eight RCTs (4147 women). The quality of evidence ranged from very low to low. The main limitations were imprecision, performance bias, and attrition bias.Hyaluronic acid selected sperm-intracytoplasmic sperm injection (HA-ICSI) compared to ICSITwo RCTs compared the effects of HA-ICSI versus ICSI on live birth. The quality of the evidence was low. There may be little or no difference between groups: 25% chance of live birth with ICSI versus 24.5% to 31% with HA-ICSI (RR 1.09, 95% CI 0.97 to 1.23, 2903 women, I2 = 0%, low-quality evidence). Three RCTs reported on miscarriage. HA-ICSI may decrease miscarriage per woman randomly assigned: 7% chance of miscarriage with ICSI versus 3% to 6% chance with HA-ICSI (RR 0.61, 95% CI 0.45 to 0.83, 3005 women, I2 = 0%, low-quality evidence) and per clinical pregnancy: 20% chance of miscarriage with ICSI compared to 9% to 16% chance with HA-ICSI (RR 0.62, 95% CI 0.46 to 0.82, 1065 women, I2 = 0%, low-quality evidence). Four RCTs reported on clinical pregnancy. There may be little or no difference between groups: 37% chance of pregnancy with ICSI versus 34% to 40% chance with HA-ICSI (RR 1.00, 95% CI 0.92 to 1.09, 3492 women, I2 = 0%, low-quality evidence).HA-ICSI compared to SpermSlowOne RCT compared HA-ICSI to SpermSlow. The quality of the evidence was very low. We are uncertain whether HA-ICSI improves live birth compared to SpermSlow (RR 1.13, 95% CI 0.64 to 2.01, 100 women) or clinical pregnancy (RR 1.05, 95% CI 0.66 to 1.68, 100 women). We are uncertain whether HA-ICSI reduces miscarriage per woman (RR 0.80, 95% CI 0.23 to 2.81, 100 women) or per clinical pregnancy (RR 0.76, 95% CI 0.24 to 2.44, 41 women).Magnetic-activated cell sorting (MACS) compared to ICSIOne RCT compared MACS to ICSI for live birth; three reported clinical pregnancy; and two reported miscarriage. The quality of the evidence was very low. We are uncertain whether MACS improves live birth (RR 1.95, 95% CI 0.89 to 4.29, 62 women) or clinical pregnancy (RR 1.05, 95% CI 0.84 to 1.31, 413 women, I2 = 81%). We are also uncertain if MACS reduces miscarriage per woman (RR 0.95, 95% CI 0.16 to 5.63, 150 women, I2 = 0%) or per clinical pregnancy (RR 0.51, 95%CI 0.09 to 2.82, 53 women, I2=0)Zeta sperm selection compared to ICSIOne RCT evaluated Zeta sperm selection. The quality of the evidence was very low. We are uncertain of the effect of Zeta sperm selection on live birth (RR 2.48, 95% CI 1.34 to 4.56, 203 women) or clinical pregnancy (RR 1.82, 95% CI 1.20 to 2.75, 203 women). We are also uncertain if Zeta sperm selection reduces miscarriage per woman (RR 0.73, 95% CI 0.16 to 3.37, 203 women) or per clinical pregnancy (RR 0.41, 95% CI 0.10 to 1.68, 1 RCT, 62 women).MACS compared to HA-ICSIOne RCT compared MACS to HA-ICSI. This study did not report on live birth. The quality of the evidence was very low. We are uncertain of the effect on miscarriage per woman (RR 1.52, 95% CI 0.10 to 23.35, 78 women) or per clinical pregnancy (RR 1.06, 95% CI 0.07 to 15.64, 37 women). We are also uncertain of the effect on clinical pregnancy (RR 1.44, 95% CI 0.91 to 2.27, 78 women).

AUTHORS' CONCLUSIONS

The evidence suggests that sperm selected by hyaluronic acid binding may have little or no effect on live birth or clinical pregnancy but may reduce miscarriage. We are uncertain of the effect of Zeta sperm selection on live birth, clinical pregnancy, and miscarriage due principally to the very low quality of the evidence for this intervention. We are uncertain of the effect of the other selection techniques on live birth, miscarriage, or pregnancy.Further high-quality studies, including the awaited data from the identified ongoing studies, are required to evaluate whether any of these advanced sperm selection techniques can be recommended for use in routine practice.

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.

Impact of high magnification sperm selection on neonatal outcomes: a retrospective study

PURPOSE

The aim of this study was to compare the effect of the deselection of spermatozoa presenting vacuole-like structures using IMSI (intracytoplasmic morphologically selected sperm injection) with ICSI (intracytoplasmic sperm injection) by means of neonatal outcomes.

METHODS

In a retrospective two-center analysis, a total of 848 successful IMSI or ICSI cycles ending with a live birth, induced abortion, or intrauterine fetal death (IUFD) were included.

RESULTS

The IMSI and ICSI groups included 332 and 655 babies or fetuses, respectively. The parents were older in the IMSI group than in the ICSI group (mothers were 35.1 vs 32.9 years, and fathers were 39.1 vs 36.2 years). The multiple pregnancy rate was higher in the IMSI group. The mean pregnancy duration and mean birth weight were almost identical in both groups. There was no significant difference in major congenital malformations between the two groups. However, this rate was decreased in the IMSI group compared to that in the ICSI group (1.8 vs 3.2%), the difference being mainly found in singletons (1.4 vs 3.3%). Boys were more often affected than girls in both groups. The percentages of chromosomal abnormalities did not differ between the IMSI and ICSI groups (0.6 and 0.8%). The reported congenital malformations mainly affected the heart, urogenital, and musculoskeletal systems.

CONCLUSIONS

In the present study, the malformation rates observed in the IMSI and ICSI groups were not significantly different, even if slightly lower after IMSI. However, the observed difference followed the same trends observed in previous reports, indicating the possible impact of IMSI on decreasing congenital malformation occurrences. This highlights the necessity to prospectively evaluate the impact of IMSI on neonatal outcome after IVF treatment.

Can intracytoplasmic Morphologically Selected Spermatozoa Injection be Used as First Choice of Treatment for Severe Male Factor Infertility Patients?

Aim:

This study was carried out to assess the outcome of the intracytoplasmic morphologically selected sperm injection (IMSI) technique compared with the previous failed intracytoplasmic sperm injection (ICSI) attempts in oligoasthenoteratozoospermia (OAT)/severe OAT (SOAT)/teratozoospermia patients.

Setting:

Institution-based, in vitro fertilization center.

Study Design:

It was a nonrandomized prospective study including 57 couples who had previous one or two ICSI failures (failure due to no implantation as embryos were transferred in these cycles and had no pregnancy) due to male factor. There was no case of total fertilization failure. IMSI was carried out in these couples and the results were compared with their previously failed ICSI attempts.

Materials and Methods:

Real-time selection of sperms was done using IMSI as it allows the assessment of fine nuclear morphology and vacuoles in the sperm head at a high magnification (>6000×) with differential interference contrast optics. Therefore, IMSI was applied in couples having OAT, SOAT or teratozoospermia as male factor and the results were compared with their previous failed ICSI attempts. Statistical analysis was carried out using GraphPad Prism.

Results and Conclusion:

Data analysis demonstrated significant difference in the fertilization rate between IMSI and previous ICSI attempts of these patients (30.0% vs. 52.0%; P < 0.05). The embryo quality, implantation and pregnancy rates with IMSI were also significantly higher than those of their previous ICSI cycles (32% vs. 56.4%; 30.2% vs. 68.5%; 0.0% vs. 62.4%; P < 0.05). Our conclusion is that the IMSI procedure improved embryo development and the clinical outcomes in the same infertile couples with male infertility and poor embryo development over their previous ICSI attempts and can be taken up as the treatment of choice in cases of severe male factor infertility.

An investigation of the potential effect of sperm nuclear vacuoles in human spermatozoa on DNA fragmentation using a neutral and alkaline Comet assay

Presence of vacuoles and degree of sperm DNA damage are considered to be the basic factors used for the assessment of sperm fertilization capacity. We aimed to investigate the link between these two parameters. According to our knowledge, this is the first study where the Comet assay was used to assess the degree of DNA fragmentation of sperm categorized by Motile Sperm Organelle Morphology Examination (MSOME) Grades. Semen samples from 10 patients were assessed. Spermatozoa were graded into four MSOME groups according to the Vanderzwalmen's criteria. A total of 3930 motile spermatozoa were selected one-by-one using an inverted microscope and transferred onto two different slides. The degree of DNA fragmentation was analyzed by alkaline and neutral Comet assay. Results of the neutral Comet assay showed that Grade I spermatozoa (absence of vacuoles) presented significantly lower dsDNA fragmentation level (mean: 3.13 ± 1.17%) than Grade II (maximum of two small vacuoles; mean: 10.34 ± 2.65%), Grade III (more than two small vacuoles or at least one large vacuole; mean: 23.88 ± 8.37%), and Grade IV (large vacuoles associated with abnormal head shapes or other abnormalities; mean: 36.94 ± 7.78%; p < 0.05). Results of the alkaline Comet assay showed that Grade I spermatozoa had significantly lower DNA (ssDNA + dsDNA) fragmentation level (mean: 8.33 ± 3.62%) than Grade III (mean: 25.64 ± 9.15%) and Grade IV (mean: 40.10 ± 9.10%, p < 0.05), but not significantly lower than Grade II (mean: 12.73 ± 5.06%; p > 0.05). Probably, the vacuoles may be responsible for double strand DNA breaks rather than single strand DNA breaks (only 2.39% spermatozoa in MSOME Grade II, 1.76% in III, and 3.16% in IV has single strand breaks). The results demonstrate that lower MSOME grading correlates with lower sperm DNA fragmentation. Therefore, the observation of sperm nuclear vacuoles using real-time optical microscopy without precise DNA fragmentation examination is not sufficient for optimal sperm selection for intracytoplasmic sperm injection.

[Methyltransferase inhibitor BIX01294 promotes the migration and inhibits decidualization of mouse uterine stromal cells in vitro]

OBJECTIVE

To investigate the effect of BIX01294 (BIX), a methyltransferase inhibitor, on the migration and decidualization of the stromal cells in mouse uterus.

METHODS

Mouse endometrial stromal cells were isolated and cultured from the uterus of pregnant mice on day 3.5 of gestation. The migration and decidualization of mouse endometrial stromal cells treated with BIX at different concentrations were observed with wound healing assay and real-time PCR.

RESULTS

The migration distance of mouse endometrial stromal cells increased as the BIX concentration increased within the range below 15 µmol/L. Compared with the control cells, the cells treated with BIX (15 µmol/L) showed significantly increased migration distances, but increasing BIX concentration to 20 µmol/L did not further increase the cell migration distance and began to cause cell death. Compared with the control cells, the BIX-treated stromal cells exhibited significantly down-regulated expression of Ehmt2 mRNA, and 15 µmol/L BIX caused inhibition of decidualization in the stromal cells.

CONCLUSION

Within a defined concentration range, BIX promotes the migration and inhibits decidualization of mouse uterine stromal cells by inhibiting the expression of Ehmt2 mRNA.

Improving ICSI: A review from the spermatozoon perspective

Intracytoplasmic sperm injection (ICSI) is the most frequently applied method for fertilization making the process of identifying the perfect spermatozoon fundamental. Herein we offer a critical and thorough presentation on the techniques reported regarding (i) handling and preparing semen samples, (ii) identifying and 'fishing' spermatozoa, and (iii) improving key factors, such as motility for a successful ICSI practice. These approaches are suggested to make the process easier and more effective especially in atypical and challenging circumstances. Furthermore, we present an epigrammatic opinion-where appropriate-based upon our collective experience. Techniques such as intracytoplasmic morphologically selected sperm injection, hyaluronic binding, polarized light microscopy, and annexin V agent identification for comparing sperm cells and their chromatin integrity are analyzed. Moreover, for the demanding cases of total sperm immotility the use of the hypoosmotic swelling test, methylxanthines, as well as the option of laser assisted immotile sperm selection are discussed. Finally, we refer to the employment of myoinositol as a way to bioreactively improve ICSI outcome for oligoasthenoteratozoospermic men. The diversity and the constant development of novel promising techniques to improve ICSI from the spermatozoon perspective, is certainly worth pursuing. The majority of the techniques discussed are still a long way from being established in routine practices of the standard IVF laboratory. In most cases an experienced embryologist could yield the same results. Although some of the techniques show great benefits, there is a need for large scale multicenter randomized control studies to be conducted in order to specify their importance before suggesting horizontal application. Taking into consideration the a priori invasive nature of ICSI, when clinical application becomes a possibility we need to proceed with caution and ensure that in the pursuit for innovation we are not sacrificing safety and the balance of the physiological and biological pathways of the spermatozoon's dynamic.

ABBREVIATIONS

ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilization; PGD: reimplantation genetic diagnosis; IVM: in vitro maturation; HCV/HIV: hepatitis C virus/human immunodeficiency virus; IMSI: intracytoplasmic morphologically selected sperm injection; DGC: density gradient centrifugations; S-U: swim-up; ART: assisted reproduction technology; IUI: intrauterine insemination; PVP: polyvinylpyrrolidone; HA: hyaluronic acid; MSOME: motile sperm organelle morphology examination; ZP: zona pellucida; MACS: magnetic activation cell sorting; HOST: hypo-osmotic swelling test; TESE: testicular sperm extraction; MMP: mitochondrial membrane potential; OAT: oligoasthenoteratozoospermic.

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.

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

PURPOSE

Assessment of sperm morphology has been reconsidered since 2001 with the development of motile sperm organelle morphology examination (MSOME). This observation technique that combines high magnification microscopy and the Nomarski interference contrast makes it possible to select spermatozoa with as few vacuoles as possible before microinjection into the oocyte (intracytoplasmic morphologically selected sperm injection, IMSI). More than 10 years after the development of IMSI, the indications of the IMSI technique and its ability to increase pregnancy and/or birthrates (compared with conventional ICSI) are still subject to debate. We aimed to better define the interest of IMSI in the third attempt.

METHODS

We assessed the benefit of IMSI by carrying out a retrospective comparative study between IMSI and conventional ICSI during a third ART attempt. Two hundred sixteen couples with two previous ICSI failures were studied between February 2010 and June 2014.

RESULTS

IMSI did not significantly improve the clinical outcomes compared with ICSI, either for implantation (12 vs 10%), clinical pregnancy (23 vs 21%), or live birth rates (20 vs 19%).

CONCLUSION

This study provides supplementary arguments for not achieving IMSI procedure in the third attempt after two previous ICSI failures.

The IMSI Procedure Improves Laboratory and Clinical Outcomes Without Compromising the Aneuploidy Rate When Compared to the Classical ICSI Procedure

PURPOSE

The intracytoplasmic morphologically selected sperm injection (IMSI) procedure has been associated with better laboratory and clinical outcomes in assisted reproduction technologies. Less information is available regarding the relationship between embryo aneuploidy rate and the IMSI procedure. The aim of this study is to compare the clinical outcomes and chromosomal status of IMSI-derived embryos with those obtained from intracytoplasmic sperm injection (ICSI) in order to establish a clearer view of the benefits of IMSI in infertile patients.

METHODS

We retrospectively analyzed a total of 11 cycles of IMSI and 20 cycles of ICSI with preimplantation genetic diagnosis. The fertilization rate, cleavage rate, embryo quality, blastocyst development, aneuploidy rate, pregnancy rate, implantation rate, and miscarriage rate were compared between the groups.

RESULTS

Similar rates of fertilization (70% and 73%), cleavage (98% and 100%), and aneuploidy (76.9% and 70.9%) were observed in the IMSI and ICSI groups, respectively. The IMSI group had significantly more good quality embryos at day 3 (95% vs 73%), higher blastocyst development rates (33% vs 19%), and greater number of hatching blastocysts (43% vs 28%), cycles with at least one blastocyst at day 5 (55% vs 35%), and blastocysts with good trophoectoderm morphology (21% vs 6%) compared with the ICSI group (P < 0.001). Significantly higher implantation rates were observed in the IMSI group compared with the ICSI group (57% vs 27%; P < 0.05). Pregnancy and miscarriage rates were similar in both groups (80% vs 50% and 0% vs 33%, respectively).

CONCLUSION

The IMSI procedure significantly improves the embryo quality/development by increasing the implantation rates without affecting the chromosomal status of embryos. There is a tendency for the IMSI procedure to enhance the pregnancy rates and lower the miscarriage rates when compared with ICSI.

Intracytoplasmic morphologically selected sperm injection versus conventional intracytoplasmic sperm injection: a randomized controlled trial

BACKGROUND

Intracytoplasmic morphologically selected sperm injection (IMSI) is still proposed and employed in the clinical practice to improve the reproductive outcome in infertile couples scheduled for conventional intracytoplasmic sperm injection (cICSI). The aim of the current randomized controlled trial (RCT) was to test the hypothesis that IMSI gives a better live birth delivery rate than cICSI.

METHODS

Infertile couples scheduled for their first cICSI cycle for male factor were allocated using a simple randomization procedure. All available biological and clinical data were recorded and analyzed in a triple-blind fashion.

RESULTS

Our final analysis involved the first 121 patients (48 and 73 subjects for IMSI and cICSI arm, respectively) because the trial was stopped prematurely on the advice of the data safety and monitoring Committee because of concerns about IMSI efficacy at the first interim analysis. No significant difference between arms was detected in rates of clinical pregnancy per embryo transferred [11/34 (32.3%) vs. 15/64 (23.4%); odds ratio (OR) 1.56, 95% (confidence interval) CI 0.62-3.93, P = 0.343] and of live birth delivery [9/48 (18.8%) vs. 11/73 (15.1%); OR 1.30, 95%CI 0.49-3.42, P = 0.594).

CONCLUSION

Current data did not support the routine use of IMSI in the clinical practice for improving cICSI results in unselected infertile couples with male factor.

The impact of paternal factors on cleavage stage and blastocyst development analyzed by time-lapse imaging-a retrospective observational study

PURPOSE

Various time-lapse studies have postulated embryo selection criteria based on early morphokinetic markers. However, late paternal effects are mostly not visible before embryonic genome activation. The primary objective of this retrospective study was to investigate whether those early morphokinetic algorithms investigated by time-lapse imaging are reliable enough to allow for the accurate selection of those embryos that develop into blastocysts, while of course taking into account the correlation with the type of injected spermatozoa.

METHODS

During a period of 18 months, a total of 461 MII oocytes from 43 couples with severe male factor infertility and previous "external" IVF failures after cleavage-stage embryo transfer (ET) were fertilized by intracytoplasmic morphologically selected sperm injection (IMSI). Thereof, 373 embryos were monitored in a time-lapse incubator until ET on day 5. Blastocyst outcome in combination with three previously postulated MKc (cc2: t3-t2, 5-12 h; t3, 35-40 h; t5, 48-56 h) and the morphology of the selected sperm were analyzed.

RESULTS

A significant increase in the rate of blastocysts (54.0 vs. 36.3 %; P < 0.01) and top blastocysts (25.3 vs. 10.8 %; P < 0.001) was observed in the group of those meeting all three morphokinetic criteria (MKc3). However, MKc3 were only met in 23.3 % of all embryos. Moreover, TBR was influenced by the type of injected spermatozoa. In both groups, TBR decreased dramatically (MKc3, 35.0 vs. 17.0 %; MKc < 3, 14.2 vs. 8.4 %) when class II/III sperm instead of class I were injected.

CONCLUSION

Early morphokinetic parameters might give some predictive information but fail to serve as a feasible selective tool for the prediction of blastocyst development given the influence of the type of spermatozoa injected.

Can intra cytoplasmatic morphologically selected sperm injection (IMSI) technique improve outcome in patients with repeated IVF-ICSI failure? a comparative study

OBJECTIVE

Spermatozoal morphology was reported to effect fertilization, embryo quality and pregnancy results in spontaneous conception and ART. Intracytoplasmic morphologically selected sperm injection (IMSI) is an innovative, not invasive technique, which examines the sperm with no harm at a magnification of 6000 × in order to obtain optimal sperm to perform IVF-ICSI. We evaluated the efficiency of IMSI technique in patients with repeated IVF-ICSI failure of at least three cycles with no viable pregnancy and/or very poor sperm quality.

STUDY DESIGN AND METHODS

All couples who performed IMSI between the years 2009 to 2012 were enrolled retrospectively to the study. Couples with male infertility who were treated with IMSI were included in the study. All their treatments were evaluated and divided into two subgroups: conventional IVF-ICSI treatment and their subsequent IMSI treatment. Demographic data, clinical parameters and outcome were recorded. The IMSI treatments were compared to previous non-IMSI treatments in terms of fertilization rates, cleavage rates, number of embryos and their quality, number of embryos transferred and pregnancy outcome.

MAIN RESULTS

Forty-two couples were reviewed. Basic characteristics of the groups were comparable. Fertilization and cleavage rates of the two groups were comparable. The embryos quality demonstrated a trend toward superior quality (grade 1-2) embryos in the IMSI versus ICSI (60% versus 47%; p = 0.07 and 53% versus 40%; p = 0.07), respectively. Implantation and clinical pregnancy rates were significantly superior in IMSI group (19.2% versus 7.8%; p = 0.042 and 41.3% versus 10.5%; p = 0.02, respectively). Miscarriage rate was significantly higher in conventional IVF-ICSI group (100% versus 15.8%; p = 0.04), and live birth rate was significantly higher in IMSI group (0 in conventional IVF-ICSI and 34.7% per transfer in IMSI group; p = 0.003).

CONCLUSION

IVF outcome of IMSI resulted in a higher implantation rate, pregnancy rate and most importantly delivery rate compare to non IMSI treated cycles.

Advanced sperm selection techniques for assisted reproduction

BACKGROUND

Assisted reproductive technologies (ART) such as in vitro fertilisation (IVF) and intracytoplasmic sperm injection (ICSI) bring together gametes outside of the body to enhance the probability of fertilisation and pregnancy. Advanced sperm selection techniques are increasingly being employed in ART, most commonly in cycles utilising ICSI. Advanced sperm selection techniques are thought to improve the chance that structurally intact and mature sperm with high DNA integrity are selected for fertilisation. Advanced sperm selection strategies include selection according to surface charge; sperm apoptosis; sperm birefringence; ability to bind to hyaluronic acid; and sperm morphology under ultra-high magnification. These techniques theoretically improve ART outcomes.

OBJECTIVES

To evaluate the impact of advanced sperm selection techniques on ART outcomes.

SEARCH METHODS

Systematic search of electronic databases (Cochrane Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Latin American and Caribbean Health Science Information Database (LILACS)), trials registers (ClinicalTrials.gov, Current Controlled Trials, World Health Organization International Clinical Trials Registry Platform), conference abstracts (Web of Knowledge) and grey literature (OpenGrey) for relevant randomised controlled trials. We handsearched the reference lists of included studies and similar reviews. The search was conducted in May 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing an advanced sperm selection technique versus standard IVF or ICSI or versus another advanced sperm selection technique. We excluded studies of sperm selection using ultra-high magnification (intracytoplasmic morphologically selected sperm injection, or IMSI), as they are the subject of a separate Cochrane review. Quasi-randomised and pseudo-randomised trials were excluded. Our primary outcome measure was live birth rate per woman randomly assigned. Secondary outcome measures included clinical pregnancy per woman randomly assigned, miscarriage per clinical pregnancy and fetal abnormality per clinical pregnancy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility of studies and risk of bias, and performed data extraction. Disagreements were resolved by consultation with a third review author. Study investigators were consulted to resolve other queries that arose. Risk ratios (RRs) were calculated with 95% confidence intervals (CIs). We planned to combine studies using a fixed-effect model, if sufficient data were available. The quality of the evidence was evaluated using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methods.

MAIN RESULTS

Two RCTs were included in the review. Both evaluated sperm selection by hyaluronanic acid binding for ICSI, but only one reported live births. No studies were identified that were related to surface charge selection, sperm apoptosis or sperm birefringence.One RCT compared hyaluronanic acid binding versus conventional ICSI. Live birth was not reported. Evidence was insufficient to show whether there was a difference between groups in clinical pregnancy rates (RR 1.01, 95% CI 0.84 to 1.22, one RCT, 482 women). This evidence was deemed to be of low quality, mainly as the result of poor reporting of methods and findings. Miscarriage data were unclear, and fetal abnormality rates were not reported.The other RCT compared two different hyaluronanic acid binding techniques, SpermSlow and physiological intracytoplasmic sperm injection (PISCI). Evidence was insufficient to indicate whether there was a difference between groups in rates of live birth (RR 1.16, 95% CI 0.65 to 2.05, one RCT, 99 women), clinical pregnancy (RR 1.07, 95% CI 0.67 to 1.71, one RCT, 99 women) or miscarriage (RR 0.76, 95% CI 0.24 to 2.44, one RCT, 41 women). The evidence for these comparisons was deemed to be of low quality, as it was limited by imprecision and poor reporting of study methods. Fetal abnormality rates were not reported.

AUTHORS' CONCLUSIONS

Evidence was insufficient to allow review authors to determine whether sperm selected by hyaluronanic acid binding improve live birth or pregnancy outcomes in ART, and no clear data on adverse effects were available. Evidence was also insufficient to show whether there is a difference in efficacy between the hyaluronic acid binding methods SpermSlow and PICSI. No randomised evidence evaluating sperm selection by sperm apoptosis, sperm birefringence or surface charge was found.Further studies of suitable quality are required to evaluate whether any of these advanced sperm selection techniques can be recommended for use in clinical practice.

Endometrial stromal cells and decidualized stromal cells: origins, transformation and functions

Decidualization of endometrium, which is characterized by endometrial stromal cell (ESC) decidualization, vascular reconstruction, immune cell recruitment, and plentiful molecule production, is a crucial step for uterus to become receptive for embryo. When implantation takes place, ESCs surround and directly interact with embryo. Decidualized stromal cells (DSCs) are of great importance in endometrial decidualization, having a broad function in regulating immune activity and vascular remodeling of uterus. DSCs are shown to have a higher metabolic level and looser cytoskeleton than ESCs. What's the origin of ESCs and how ESCs successfully transform into DSCs had puzzled scientists in the last decades. Breakthrough had been achieved recently, and many studies had elucidated some of the characters and functions of DSCs. However, several questions still remain unclear. This paper reviews current understanding of where ESCs come from and how ESCs differentiate into DSCs, summarizes some characters and functions of DSCs, analyzes current studies and their limitations and points out research areas that need further investigation.

Clinical and structural features of sperm head vacuoles in men included in the in vitro fertilization programme

The human sperm head vacuoles and their role in male infertility are still poorly understood. The aim of this study was to identify the clinical and ultrastructural features of human sperm head vacuoles in men included in the in vitro fertilization programme: men with normal (normozoospermia) and impaired sperm morphology (teratozoospermia). The sperm samples were observed under 6000-time magnification using motile sperm organelle morphology examination (MSOME). The proportion of sperm with head vacuoles was evaluated and related to the outcome of in vitro fertilization. The sperm of men with impaired sperm morphology was characterized by a higher proportion of sperm head vacuoles. The sperm head vacuoles were related to impaired semen quality (sperm concentration, motility, and morphology) but were not influenced by male factors (semen volume, height, age, weight, or body mass index). Moreover, sperm head vacuoles were related to impaired fertilization rate merely after classical in vitro fertilization (IVF), while there was no relation to pregnancy. In a subgroup of men, the sperm was fixed and observed by transmission electron microscopy (TEM). The ultrastructural study revealed that sperm head vacuoles are large nuclear indentations of various sizes and positions, packed with membranous material organized in membrane whorls (MW).

New advances of preimplantation and prenatal genetic screening and noninvasive testing as a potential predictor of health status of babies

The current morphologically based selection of human embryos for transfer cannot detect chromosome aneuploidies. So far, only biopsy techniques have been able to screen for chromosomal aneuploidies in the in vitro fertilization (IVF) embryos. Preimplantation genetic diagnosis (PGD) or screening (PGS) involves the biopsy of oocyte polar bodies or embryonic cells and has become a routine clinical procedure in many IVF clinics worldwide, including recent development of comprehensive chromosome screening of all 23 pairs of chromosomes by microarrays for aneuploidy screening. The routine preimplantation and prenatal genetic diagnosis (PND) require testing in an aggressive manner. These procedures may be invasive to the growing embryo and fetus and potentially could compromise the clinical outcome. Therefore the aim of this review is to summarize not only the new knowledge on preimplantation and prenatal genetic diagnosis in humans, but also on the development of potential noninvasive embryo and fetal testing that might play an important role in the future.

Comparison between intracytoplasmic sperm injection and intracytoplasmic morphologically selected sperm injection in oligo-astheno-teratozoospermia patients

Objective

The aim of this study was to evaluate the efficiency of the intracytoplasmic morphologically selected sperm injection (IMSI) technique compared with conventional ICSI and previous ICSI attempts in oligo-astheno-teratozoospermia (OAT) patients.

Methods

The sperms were selected under high magnification (6,600×) and used to induce fertilization in previous ICSI patients by IMSI. These results were compared with previous conventional ICSI cycles in patients with OAT infertility.

Results

These results demonstrated no significant difference in the fertilization rate between IMSI and previous ICSI cycles (67.7% vs. 65.0%). However, the pregnancy and implantation rates with IMSI were significantly higher than those of the ICSI cycles (33.3% vs. 12.5% and 14.6% vs. 5.4%, respectively; p<0.05). The miscarriage rate among pregnant patients (18.2% vs. 37.5%) showed no statistically significant difference between groups.

Conclusion

Compared to conventional ICSI, this study found that IMSI increased the IVF-ET success rates in patients with OAT.

Some reflections on intracytoplasmic morphologically selected sperm injection

Although intracytoplasmic sperm injection (ICSI) allows proper fertilization in most cases of male sub fertility, it is one of the most unphysiological techniques in assisted reproductive technologies (ART). Thus, over the last decade, researchers have tried to improve sperm observation with higher-resolution microscopy techniques such as the intracytoplasmic morphologically selected sperm injection (IMSI) technique. In order to identify literatures for this review, the PubMed database was searched from 2000 onwards using the terms IMSI, motile sperm organelle morphology examination (MSOME) and sperm vacuole. Approximately 10 years after the introduction of the MSOME and IMSI procedures, several questions related to the prevalence, origin, location, and clinical consequences of sperm vacuoles have not yet been clarified. It seems that IMSI as a routine application is not state of the art and the only confirmed indications for IMSI are recurrent implantation failure following ICSI and severe male factor.

The prevalence of sperm with large nuclear vacuoles is a prognostic tool in the prediction of ICSI success

PURPOSE

To investigate if there is a correlation between the prevalence of sperm with large nuclear vacuoles (LNV) and intracytoplasmic sperm injection (ICSI) outcomes.

METHODS

Two hundred male patients undergoing ICSI had their sperm morphology evaluated through motile sperm organelle morphology examination (MSOME) and the percentage of LNV sperm was recorded and correlated to the ICSI outcomes.

RESULTS

The percentage of sperm with LNV negatively influenced the blastocyst formation (S: 16.9, R(2): 20.5%, p = 0.004) and implantation (S: 34.7, R(2): 26.2%, p = 0.001). There were significant differences in the percentage of sperm with LNV between patients in which pregnancy was achieved or not (22.2% vs. 28.4%, p < 0.001) and in patients with ongoing pregnancy or not (22.4% vs. 28.5%, p < 0.001). The incidence of sperm with LNV was determinant to the decreased odds of pregnancy (OR: 0.74, p < 0.001) and increased odds of miscarriage (OR: 1.46, p < 0.001). The area under the curve (AUC) was sufficient to distinguish between couples which did achieve pregnancy or not (AUC: 0.922, p < 0.001).

CONCLUSIONS

The MSOME is a prognostic tool in the prediction of ICSI success and could be used to select patients that should have their sperm selected by MSOME for ICSI.

Intracytoplasmic morphologically selected sperm injection (IMSI): a critical and evidence-based review

Introduced in 2001, intracytoplasmic morphologically selected sperm injection (IMSI) represents a more sophisticated way of ICSI whereby, prior to injection, the spermatozoon is selected at higher magnification. Doing so, the spermatozoon can be evaluated for fine integrity of its nucleus and the injection of a normal spermatozoon with a vacuole-free head can be assured.

Additional research is needed to unravel the underlying mechanisms responsible for the presence of vacuoles in sperm heads. Associations with acrosome status, chromatin condensation, DNA fragmentation and sperm aneuploidy have been documented, however, controversy on their nature exists. Spermatozoon shape and large vacuoles are detected and deselected in conventional ICSI as well. However, the detection of subtle small vacuoles depends on the resolving power of the optical system and may impact oocyte fertilization, embryo development and implantation.

Several comparative studies have indicated that the use of high-magnification sperm selection was associated with both higher pregnancy and delivery rates, whereas also lower miscarriage rates were observed. However, still to date randomized, well-powered studies to confirm these findings are scarce and show conflicting results. Hence, the most relevant indications for IMSI still remain to be determined. Two groups of patients have been put forward i.e. severe male-factor infertility patients and patients with a history of repeated ICSI failures. However, for both groups limited to no proof of any benefit does exist.

IMSI is a time-consuming procedure at the expense of oocyte ageing. The lack of proof and understanding of its benefit does not justify its routine clinical application at present.

High-magnification selection of spermatozoa prior to oocyte injection: confirmed and potential indications

Intracytoplasmic morphologically selected sperm injection (IMSI) involves the use of differential interference contrast microscopy at high magnification (at least ·6300) to improve the observation of live human spermatozoa (particularly by showing sperm head vacuoles that are not necessarily seen at lower magnifications) prior to intracytoplasmic sperm injection (ICSI) into the oocyte. However, a decade after IMSI’s introduction, the technique’s indications and ability to increase pregnancy and/or birth rates (relative to conventional ICSI) are subject to debate. In an attempt to clarify this debate, this work performed a systematic literature review according to the PRISMA guidelines. The PubMed database was searched from 2001 onwards with the terms ‘IMSI’, ‘MSOME’ and ‘high-magnification, sperm’. Out of 168 search results, 22 relevant studies reporting IMSI outcomes in terms of blastocyst, pregnancy, delivery and/or birth rates were selected and reviewed. The studies’ methodologies and results are described and discussed herein. In view of the scarcity of head-to-head IMSI versus ICSI studies, the only confirmed indication for IMSI is recurrent implantation failure following ICSI. All other potential indications of IMSI require further investigation.

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. Recently a new method of sperm selection named 'motile sperm organelle morphology examination' (MSOME) has been described and the spermatozoa selected under high magnification (over 6000x) used for ICSI. This new technique, named intracytoplasmic morphologically selected sperm injection (IMSI), has a theoretical potential to improve reproductive outcomes among couples undergoing assisted reproduction techniques (ART).

OBJECTIVES

To compare the effectiveness and safety of IMSI and ICSI in couples undergoing ART.

SEARCH METHODS

We searched for randomised controlled trials (RCT) in electronic databases (Cochrane Menstrual Disorders and Subfertility Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS), trials registers (ClinicalTrials.gov, Current Controlled Trials, World Health Organization International Clinical Trials Registry Platform), conference abstracts (ISI Web of knowledge), and grey literature (OpenGrey); in addition, we handsearched the reference lists of included studies and similar reviews. We performed the last electronic search on 8 May 2013.

SELECTION CRITERIA

We considered only truly randomised controlled trials comparing ICSI and IMSI to be eligible; we did not include quasi or pseudo-randomised trials. We included 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 we solved disagreements by consulting a third review author. We corresponded with study investigators in order to resolve any queries, as required.

MAIN RESULTS

The search retrieved 294 records; from those, nine parallel design studies were included, comprising 2014 couples (IMSI = 1002; ICSI = 1012). Live birth was evaluated by only one trial and there was no significant evidence of a difference between IMSI and ICSI (risk ratio (RR) 1.14, 95% confidence interval (CI) 0.79 to 1.64, 1 RCT, 168 women, I(2) = not applicable, low-quality evidence). IMSI was associated with a significant improvement in clinical pregnancy rate (RR 1.29, 95% CI 1.07 to 1.56, 9 RCTs, 2014 women, I(2) = 57%, very-low-quality evidence). We downgraded the quality of this evidence because of imprecision, inconsistency, and strong indication of publication bias. We found no significant difference in miscarriage rate between IMSI and ICSI (RR 0.82, 95% CI 0.59 to 1.14, 6 RCTs, 552 clinical pregnancies, I(2) = 17%, very-low-quality evidence). None of the included studies reported congenital abnormalities.

AUTHORS' CONCLUSIONS

Results from RCTs do not support the clinical use of IMSI. There is no evidence of effect on live birth or miscarriage and the evidence that IMSI improves clinical pregnancy is of very low quality. There is no indication that IMSI increases congenital abnormalities. Further trials are necessary to improve the evidence quality before recommending IMSI in clinical practice.

Focus on intracytoplasmic morphologically selected sperm injection (IMSI): a mini-review

Intracytoplasmic sperm injection (ICSI) is the recommended treatment in many cases of male-factor infertility. Several studies have demonstrated a positive correlation between optimal sperm morphology and positive ICSI outcomes. In fact, spermatozoa with severe abnormalities of the head are well documented to be associated with low fertilisation, implantation and pregnancy rates. However, a spermatozoon which is classified as 'normal' by microscopic observation at low magnification could contain ultrastructural defects that impair both the fertilisation process and embryonic development. The intracytoplasmic morphologically selected sperm injection (IMSI) procedure changed the perception of how a spermatozoon suitable for injection should appear. Sperm selection is carried out at ×6000 magnification, allowing improved assessment of the sperm nucleus. Currently, standardized clinical indications for IMSI are lacking and the candidates are selected on the grounds of their medical history or of a careful analysis of the sperm suspension. Further prospective randomized studies are needed to confirm the advantages of IMSI in specific groups of patients. In addition to providing a brief overview of the IMSI procedure, this study aims to review the literature, which explains the theoretical basis and the clinical outcomes of this technique. Several reports show that IMSI is associated with improved implantation and clinical pregnancy rates as well as lower abortion rates when compared to ICSI. Although a possible correlation between the sperm's abnormal nucleus shape, increased DNA fragmentation and negative laboratory and clinical outcomes has been long investigated, the results are conflicting.

Motile sperm organelle morphology examination (MSOME) and sperm head vacuoles: state of the art in 2013

BACKGROUND Approximately 10 years after the first publication introducing the motile sperm organelle morphology examination (MSOME), many questions remained about sperm vacuoles: frequency, size, localization, mode of occurrence, biological significance and impact on male fertility potential. Many studies have tried to characterize sperm vacuoles, to determine the sperm abnormalities possibly associated with vacuoles, to test the diagnostic value of MSOME for male infertility or to question the benefits of intracytoplasmic morphologically selected sperm injection (IMSI). METHODS We searched PubMed for articles in the English language published in 2001-2012 regarding human sperm head vacuoles, MSOME and IMSI. RESULTS A bibliographic analysis revealed consensus for the following findings: (i) sperm vacuoles appeared frequently, often multiple and preferentially anterior; (ii) sperm vacuoles and sperm chromatin immaturity have been associated, particularly in the case of large vacuoles; (iii) teratozoospermia was a preferred indication of MSOME and IMSI. CONCLUSION The high-magnification system appears to be a powerful method to improve our understanding of human spermatozoa. However, its clinical use remains unclear in the fields of male infertility diagnosis and assisted reproduction techniques (ARTs).

Twelve years of MSOME and IMSI: a review

A promising method for observing spermatozoa, motile sperm organelle morphology examination (MSOME) enables the evaluation of the nuclear morphology of motile spermatozoa in real time at high magnification and has allowed the introduction of a modified microinjection procedure, intracytoplasmic morphologically selected sperm injection (IMSI). Since its development, several studies have intensively investigated the efficacy of MSOME and IMSI. The objective of the present study is to review the current literature on the MSOME and IMSI techniques. A promising method for observing spermatozoa, motile sperm organelle morphology examination (MSOME), enables the evaluation of the nuclear morphology of motile spermatozoa in real time at high magnification and has allowed the introduction of a modified microinjection procedure, intracytoplasmic morphologically selected sperm injection (IMSI). Since its development, several studies have intensively investigated the efficacy of MSOME and IMSI. The objective of the present study is to review the current literature on the MSOME and IMSI techniques.