Is intracytoplasmic morphologically selected sperm injection effective in patients with infertility related to teratozoospermia or repeated implantation failure?

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.

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.

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.

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.

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.

Outcomes of Intracytoplasmic Sperm Injection Cycles for Complete Teratozoospermia: A Case-Control Study Using Paired Sibling Oocytes

OBJECTIVE

To investigate the outcomes of intracytoplasmic sperm injection (ICSI) cycles where sibling oocytes from a single donor were split between two recipients based on strict sperm morphology.

METHODS

Retrospective cohort study. All ICSI cycles had one donor's oocytes split between two recipients in a 1 : 1 ratio based on strict sperm morphology, that is, one male partner had morphology of 0% and the other had morphology of >1%. Fertilization, positive hCG, clinical pregnancy, spontaneous miscarriage, and live birth rates of the aforementioned groups were compared.

RESULTS

The baseline characteristics of the two groups (n = 103), including semen parameters of the male partners, were comparable. There was no difference in the fertilization rates when comparing the 0% group to the >1% group (78.7% versus 81.6%; P = 0.66). The overall positive hCG, clinical pregnancy, spontaneous miscarriage, and live birth rates for the 0% group were 61.2%, 49.5%, 10.7%, and 38.8%, respectively. The corresponding rates in the >1% group were positive hCG (63.1%), clinical pregnancy (55.3%), spontaneous miscarriage (7.77%), and live birth (46.6%).

CONCLUSIONS

The fertilization and pregnancy outcomes of ICSI cycles for strict sperm morphology of 0% versus morphology of >1% are equivalent. These results can provide reassurance to couples undergoing ICSI for severe teratospermia.

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.

Could sperm grade under high magnification condition predict IMSI clinical outcome?

OBJECTIVE

The aim of this study was to examine whether injection of first-best morphology grade selected spermatozoa improves live birth rate (LBR) compared to intracytoplasmic morphologically selected sperm injection (IMSI) using second-best grade sperm.

STUDY DESIGN

In this prospective observational study, 132 patients were enrolled. Inclusion criteria were the presence of severe male factor (normal spermatozoa <10% in fresh ejaculated semen and <10% in selected sperm according to David's classification) associated with ≤2 previous ICSI failure. Results of IMSI performed with either first- or second-best morphology grade spermatozoa (according to Vanderzwalmen's classification) were compared. IMSI attempts performed using mixed first- and second-best grade spermatozoa were excluded (n=41). The primary endpoint was LBR.

RESULTS

LBR following IMSI was not statistically different using first- (33.3% (13/39)) or second-best morphology grade spermatozoa (28.9% (15/52)). Our study shows that sperm grading under high magnification using Vanderzwalmen's classification is not correlated to IMSI outcome.

CONCLUSION

We do not validate Vanderzwalmen classification in our external and prospective series. These results point out the need for improving our knowledge about the impact of observed vacuoles under high magnification condition.

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.