ART success andin vivosperm cell selection depend on the ultramorphological status of spermatozoa

Poor-responder patients do not benefit from intracytoplasmic morphologically selected sperm injection

PURPOSE

To compare the outcomes of ICSI and IMSI in women presenting with poor ovarian response.

METHODS

Data of IMSI cycles performed from January 2011 to December 2013 were included in this retrospective cohort study. Patients were divided into two groups: normoresponder patients (NR group; patients with > 4 oocytes retrieved) and poor-responder patients (PR group; patients with ≤ 4 oocytes retrieved). Patients who underwent IMSI were matched with patients who underwent ICSI in the same period. The ICSI and IMSI outcomes were compared in the NR and PR groups.

RESULTS

A total of 414 matched cycles were included in this study. The NR group comprised 324 cycles (164 ICSI and 160 IMSI cycles), and the PR group comprised 90 cycles (43 ICSI and 47 IMSI cycles). In the NR group, no significant differences were observed between the ICSI- and IMSI-treated couples regarding cycle outcomes. In the PR group, fertilisation rate was significantly lower in IMSI-treated couples (53.9% ± 36.7% vs. 79.8% ± 29.3%). The proportion of cycles with embryo transfer (57.4 vs. 79.1%) and the number of transferred embryos (1.5 ± 0.8 vs. 1.9 ± 0.7) were significantly lower in IMSI compared with ICSI. Implantation, pregnancy and miscarriage rates were similar when ICSI or IMSI were performed.

CONCLUSIONS

Our results suggest that unselected couples undergoing ICSI that present with poor ovarian response to controlled ovarian stimulation do not benefit from sperm selection under high magnification prior to ICSI.

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.

New molecular markers for the evaluation of gamete quality

PURPOSE

Only 30 % of IVF cycles result in a pregnancy, so that multiple embryos need to be replaced, per treatment cycle, to increase pregnancy rates, resulting in a multiple gestation rate of 25 %. The use of new markers in the gamete selection, could reduce the number of the oocytes to be fertilized and embryos to be produced, but the tools to evidence the gamete competence remain unavailable and more studies are needed to identify bio-markers to select the best oocyte and sperm to produce embryos with higher implantation potentiality.

METHODS

To define oocyte competence, the apoptosis of the surrounding cumulus cells and the oxygen consumption rates for individual oocytes before fertilization seems to provide a non-invasive marker of oocyte competence and hence a quantitative assessment of the reproductive potential for the oocyte. The chromatin integrity seems to be used also as biological marker of sperm competence, together with the morphological evaluation of large vacuoles in the head.

RESULTS

The apoptosis rate of cumulus cells lower than 25 % and an higher oxygen consumption could be an evidence of an overall metabolic activity, related to a better fertilization ability and embryo cleavage quality. The apoptosis rate of the sperm chromatin, evaluated by direct Tunel in situ analysis, seems to be, also for the male gamete, a marker of competence and implantation potentiality, in particular when it is lower than 20 %. The evaluation of the presence of large vacuoles in the sperm head prior to perform ICSI seems to increase the implantation rate, but it is not associated to chromatin integrity.

CONCLUSIONS

The biological concept of competence appears unrelated to any morphological parameters, so that it is necessary to investigate new molecular markers in the gamete selection. Apoptosis of cumulus cells in the oocytes and spermatozoa, revealing the presence of large vacuoles, could help to determine the competence of the gamete to be fertilize.

Observation of spermatozoa by a high-magnification microscope

Semen analyses are the primary tool for evaluating male infertility, as semen parameters are useful for predicting potential fertility. In the field of assisted reproductive technology (ART), the single best motile spermatozoon should be selected, especially when performing intracytoplasmic sperm injection (ICSI). In this context, the motile sperm organelle morphology examination (MSOME) was developed as a method of assessing the detailed morphology of motile spermatozoa in real time at a magnification of up to 6,300× on a video system. The use of ICSI with MSOME-selected sperm is called intracytoplasmic morphologically selected sperm injection (IMSI). IMSI improves the outcomes of ICSI. MSOME can be also applied to evaluate male infertility. Among MSOME parameters, the presence of sperm nuclear vacuoles is the most important finding. Large sperm nuclear vacuoles (LNV) are related not only to poor ART outcomes, but also to poor semen quality and sperm DNA damage, such as DNA fragmentation and chromatin condensation failure. It has been suggested that sperm head vacuoles are produced at earlier stages of sperm maturation. It is possible that the number of LNV can be decreased by surgical or medical treatment for male infertility. Therefore, the level of LNV has the potential to be used as an alternative parameter of semen quality and a new tool for evaluating the therapeutic effects of treatment in male patients with infertility.

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.

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.

Quality of human spermatozoa: relationship between high-magnification sperm morphology and DNA integrity

The aim of this work is to establish the relationship between the morphology of Intracytoplasmic Morphologically Selected Sperm Injection (IMSI)-selected spermatozoa and their DNA integrity. The 45 ejaculates were randomly distributed into three treatment groups: normozoospermic, oligoasthenozoospermic and oligoasthenotheratozoospermic samples. The evaluation of DNA integrity was performed using the sperm chromatin dispersion test. It was established that DNA integrity of spermatozoa is strongly dependent on ejaculate quality (P < 0.05). The count of spermatozoa with nonfragmented DNA in normozoospermic samples was high and independent from IMSI-morphological classes (Class 1 versus Class 3, respectively) (P > 0.1). With decreased ejaculate quality, the percentage of spermatozoa with nonfragmented DNA decreased significantly (P < 0.05) independent from morphological class. Nevertheless, the rate of IMSI-selected spermatozoa with fragmented DNA within of Class 1 in normozoospermic (Group 1), in oligoasthenozoospermic (Group 2) and in oligoasthenotheratozoospermic (Group 3) samples was 21.1%, 31.8% and 54.1%, respectively. In conclusion, there is a direct relationship between morphological parameters of spermatozoa and their DNA integrity. However, the IMSI technique alone is not enough for the selection of spermatozoa with intact nuclei.

Digital holographic microscopy for the evaluation of human sperm structure

The morphology of the sperm head has often been correlated with the outcome of in vitro fertilization, and has been shown to be the sole parameter in semen of value in predicting the success of intracytoplasmic sperm injection and intracytoplasmic morphologically selected sperm injection. In this paper, we have studied whether digital holographic microscopy (DHM) may be useful to obtain quantitative data on human sperm head structure and compared this technique with high-power digitally enhanced Nomarski optics. The main advantage of digital holography is that high-resolution three-dimensional quantitative sample imaging may be automatically produced by numerical refocusing of a two-dimensional image at different object planes without any mechanical scanning. We show that DHM generates useful information on the dimensions and structure of human sperm, not revealed by conventional phase-contrast microscopy, in particular the volume of vacuoles, and suggest its use as an additional prognostic tool in assisted reproduction technology.

Sperm head vacuolization affects clinical outcome in ICSI cycle. A proposal of a cut-off value

OBJECTIVE

To evaluate the relationship between sperm nuclear vacuoles and sperm morphology and to investigate the influence of the rate of spermatozoa with head vacuolization (SVR) in a seminal sample on the clinical outcomes in couples undergoing intracytoplasmic sperm injection.

MATERIALS

26 patients undergoing infertility investigations were included and were divided in two groups according to an SVR ≤ 20,28 % (Group A) or > 20,28 % (Group B), and were investigated to verify the influence of SVR on the fertilization rate, embryo quality, pregnancy and implantation rates.

RESULTS

Abnormal spermatozoa with nuclear vacuoles were significantly higher (p < 0.001) than the percentage of normal spermatozoa with nuclear vacuoles. Patients in group A had a percentage of abnormal sperm with nuclear vacuole significantly lower compared to group B (p < 0,001), but there was no difference in the percentage of normal sperm with nuclear vacuoles. Fertilization rates and the number of top quality embryos did not differ between the two groups. The pregnancy and implantation rates were significantly higher in Group A compared to Group B (respectively p < 0,05 and p < 0.001).

CONCLUSIONS

For the first time, we propose a cut off value in the proportion of sperms with nuclear vacuolization on the total of sperm in seminal samples, and demonstrate a relationship between SNV and clinical outcomes after ICSI. The SNV rate could be introduced as an easy diagnostic evaluation prior to perform an ICSI cycle.

Morphopathology of Sperm: It's Impact on Fertilization

Terato-, astheno- and necrozoospermia negatively influence fertility prognosis in spontaneous conditions or with the use of various assisted reproductive techniques including conventional in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). The correct identification of sperm pathologies will indicate different fertility potentials and outcomes in assisted reproduction technology. Anomalies of only the spermatozoa flagella bear a promising prognosis, but those affecting the sperm chromatin and the neck region entail an increasing chance of failure, which highlights the differential roles played by specific sperm components in fertilization, implantation and early embryonic development. Sperm pathology therefore allows an understanding of abnormal function that goes beyond that provided by classical sperm morphology classifications that are mainly based on descriptions of abnormal sperm shapes with no insight into the mechanisms or the pathological details.

Evaluation of ubiquitin and annexin V in sperm population selected based on density gradient centrifugation and zeta potential (DGC-Zeta)

PURPOSE

Sperm that bypass natural apoptosis and the ubiquitin-proteasome system may find their way into semen. In order to avoid the insemination of such sperm during an intracytoplasmic sperm injection (ICSI) treatment, novel sperm selection procedures such as the Zeta procedure have been implemented. Therefore, the aim of this study was to evaluate extent of ubiquitination and external phosphatidylserine (EPS) in sperm populations selected by combines density gradient centrifugation (DGC) and Zeta electric potential in comparison to DGC and neat semen samples.

METHODS

Semen samples were collected from 51 infertile men and divided into control, DGC and DGC-Zeta groups. Semen analysis was carried out according to World Health Organization criteria. The percentages of protamine deficiency, DNA fragmentation, EPS and ubiquitinated sperm were assessed by chromomycin A3 (CMA3), TUNEL, Annexin V, and immunostaining, respectively.

RESULTS

Sperm selected by the DGC-Zeta procedure presented a lower percentage of sperm with protamine deficiency, abnormal morphology and DNA fragmentation while the percentage of annexin V and ubiquitin-positive sperm increased.

CONCLUSION

The results of this study reveal that, DGC-Zeta improves the quality of the selected spermatozoa for ICSI and increases ubiquitination and EPS rates. We propose these alterations are part of the normal physiological process of capacitation.

Sperm preparation: state-of-the-art--physiological aspects and application of advanced sperm preparation methods

For assisted reproduction technologies (ART), numerous techniques were developed to isolate spermatozoa capable of fertilizing oocytes. While early methodologies only focused on isolating viable, motile spermatozoa, with progress of ART, particularly intracytoplasmic sperm injection (ICSI), it became clear that these parameters are insufficient for the identification of the most suitable spermatozoon for fertilization. Conventional sperm preparation techniques, namely, swim-up, density gradient centrifugation and glass wool filtration, are not efficient enough to produce sperm populations free of DNA damage, because these techniques are not physiological and not modeled on the stringent sperm selection processes taking place in the female genital tract. These processes only allow one male germ cell out of tens of millions to fuse with the oocyte. Sites of sperm selection in the female genital tract are the cervix, uterus, uterotubal junction, oviduct, cumulus oophorus and the zona pellucida. Newer strategies of sperm preparation are founded on: (i) morphological assessment by means of 'motile sperm organelle morphological examination (MSOME)'; (ii) electrical charge; and (iii) molecular binding characteristics of the sperm cell. Whereas separation methods based on electrical charge take advantage of the sperm's adherence to a test tube surface or separate in an electrophoresis, molecular binding techniques use Annexin V or hyaluronic acid (HA) as substrates. Techniques in this category are magnet-activated cell sorting, Annexin V-activated glass wool filtration, flow cytometry and picked spermatozoa for ICSI (PICSI) from HA-coated dishes and HA-containing media. Future developments may include Raman microspectrometry, confocal light absorption and scattering spectroscopic microscopy and polarization microscopy.

Efficacy of the motile sperm organelle morphology examination (MSOME) in predicting pregnancy after intrauterine insemination

BACKGROUND

Although the motile sperm organelle morphology examination (MSOME) was developed merely as a selection criterion, its application as a method for classifying sperm morphology may represent an improvement in the evaluation of semen quality. The aim of this study was to determine the prognostic value of normal sperm morphology using MSOME with regard to clinical pregnancy (CP) after intrauterine insemination (IUI).

METHODS

A total of 156 IUI cycles that were performed in 111 couples were prospectively analysed. Each subject received 75 IU of recombinant FSH every second day from the third day of the cycle. Beginning on the 10th day of the cycle, follicular development was monitored by vaginal ultrasound. When one or two follicles measuring at least 17 mm were observed, recombinant hCG was administered, and IUI was performed 12-14 h and 36-40 h after hCG treatment. Prior to the IUI procedure, sperm samples were analysed by MSOME at 8400× magnification using an inverted microscope that was equipped with DIC/Nomarski differential interference contrast optics. A minimum of 200 motile spermatozoa per semen sample were evaluated, and the percentage of normal spermatozoa in each sample was determined.

RESULTS

Pregnancy occurred in 34 IUI cycles (CP rate per cycle: 21.8%, per patient: 30.6%). Based on the MSOME criteria, a significantly higher percentage of normal spermatozoa was found in the group of men in which the IUI cycles resulted in pregnancy (2.6+/-3.1%) compared to the group that did not achieve pregnancy (1.2+/-1.7%; P = 0.019). Logistic regression showed that the percentage of normal cells in the MSOME was a determining factor for the likelihood of clinical pregnancy (OR: 1.28; 95% CI: 1.08 to 1.51; P = 0.003). The ROC curve revealed an area under the curve of 0.63 and an optimum cut-off point of 2% of normal sperm morphology. At this cut-off threshold, using the percentage of normal sperm morphology by MSOME to predict pregnancy was 50% sensitive with a 40% positive predictive value and 79% specificity with an 85% negative predictive value. The efficacy of using the percentage of normal sperm morphology by MSOME in predicting pregnancy was 65%.

CONCLUSIONS

The present findings support the use of high-magnification microscopy both for selecting spermatozoa and as a routine method for analysing semen before performing IUI.

An assessment of new sperm tests for male infertility

The routine semen analysis, although used for more than 50 years, fails to accurately distinguish between fertile and infertile men. As a consequence, many tests of sperm function (TSF) have been developed. This review discusses both older and newer diagnostic TSF. It outlines the principles underlying each assay and reviews aggregate clinical data to determine its current relevance and utility. It concludes that the relevance of many older TSF is questionable, with the wide acceptance of intracytoplasmic sperm injection (ICSI). Newer TSF have the potential to deliver more clinically relevant information but require more extensive study to better understand their predictive role in the ICSI era.

Les larges vacuoles des têtes spermatiques sont-elles associées à des altérations du noyau ou de l’acrosome du spermatozoïde ?

Objectifs

Rechercher la présence d’altérations nucléaires ou acrosomiques dans les spermatozoïdes présentant des vacuoles occupant au moins 13 % de la surface de la tête des spermatozoïdes (spermatozoïdes dits de type 3), détectées à l’aide de la technique MSOME (motile sperm organelle morphology examination).

Matériel et méthodes

Notre étude a été effectuée sur des recueils de sperme de 20 hommes infertiles. Une évaluation de l’acrosome par immunomarquage à l’aide d’un anticorps monoclonal antiproacrosine (Mab4D4) a été associée à une détection de la fragmentation de l’ADN par la technique TUNEL. La condensation de la chromatine spermatique a été évaluée par une coloration au bleu d’aniline, et le taux d’aneuploïdie a été déterminé par hybridation in situ en fluorescence (FISH). Une observation des échantillons spermatiques par microscopie électronique à transmission (MET) [sperme entier] et confocale [spermatozoïdes de type 3 isolés] a complété ces analyses. Les résultats ont été comparés entre des spermatozoïdes provenant du sperme entier et des spermatozoïdes de type 3 isolés.

Résultats

Une augmentation significative de la proportion d’acrosomes anormaux a été constatée dans les spermatozoïdes isolés de type 3 par comparaison au sperme entier (77,8 ± 2,49 % vs 70,6 ± 2,62 %). La fragmentation de l’ADN a été observée de manière comparable dans les spermatozoïdes de type 3 et le sperme entier (14,5 ± 3,45 % vs 11,5 ± 1,25%), un défaut de condensation de la chromatine ainsi qu’une augmentation significative du taux d’aneuploïdie ont été retrouvés dans les spermatozoïdes isolés par comparaison à ceux provenant du sperme entier (50,4 ± 3,10 % vs 26,5 ± 2,60 % et 7,8 ± 1,98 % vs 1,3 ± 0,18 %). Les larges vacuoles sont à localisation nucléaire exclusive (MET et microscopie confocale).

Conclusion

Les vacuoles seraient en relation directe avec un défaut de maturation nucléaire survenant au cours de la spermiogenèse.

How to improve IVF–ICSI outcome by sperm selection

In previous studies, a new IVF method of intracytoplasmic morphologically selected sperm injection (IMSI) was introduced, based on motile sperm organellar morphology examination (MSOME). It was concluded that microinjection of morphologically selected sperm cells with strictly normal nucleus, defined by MSOME, improves IVF-ICSI outcome. The aim of the present study was to confirm this conclusion in new, enlarged study groups. Comparison between 80 couples, who underwent an IVF-IMSI trial, with matched couples, who underwent a standard IVF-ICSI procedure, confirmed that pregnancy rate following IVF-IMSI was significantly higher, and abortion rate significantly lower than in the routine IVF-ICSI (60.0 versus 25.0%, and 14 versus 40% respectively, P <or= 0.05). Another comparison was performed between matched IMSI groups, where embryos were obtained from microinjection by spermatozoa with a morphologically normal nucleus ('best' group, n = 70) and a 'second best' group was selected, where embryos were obtained from microinjection of spermatozoa with minimal morphological impairment, since no other sperm cells were available. It was confirmed that microinjection by 'second best ' spermatozoa result in significantly lower pregnancy and delivery rates and significantly higher abortion rates than microinjection with 'best' spermatozoa (25.7 versus 58.2%, P <or= 0.01; 17.1 versus 52.8%, P <or= 0.01, and 33.3 versus 9.7%, P <or= 0.02 respectively). The present study has strengthened previous conclusions.