Evaluation of the effect of piezo-intracytoplasmic sperm injection on the laboratory, clinical, and neonatal outcomes

Polyvinylpyrrolidone can prevent oolemma lysis caused by abnormal rupture of the plasma membrane in Piezo-ICSI

The aim of this study was to investigate whether it is possible to prevent oolemma lysis after Piezo-assisted intracytoplasmic sperm injection (Piezo-ICSI) caused by abnormal membrane rupture. A total of 489 mature oocytes were obtained from 85 patients who underwent Piezo-ICSI in an infertility clinic. Inseminated oocytes were classified into the following two groups: normal rupture and abnormal rupture, and a portion of abnormally ruptured oocytes was randomly exposed to 7% PVP solution. Normal fertilization rate, degeneration rate, proportion of high-quality embryos on day 3, blastocyst formation, and morphologically high-quality blastocysts were compared. Abnormal rupture was defined as cytoplasmic membrane rupture before piezo pulse driving. Among the abnormal rupture groups, the normal fertilization and degeneration rates were compared between the high-stretched (ruptured at ≥ 50% during oocyte membrane stretching) and low-stretched (< 50% position) oocytes.The degeneration rate was significantly higher in abnormally ruptured oocytes than in normally ruptures oocytes (14.3% vs 1.3%, p < 0.001), and there was no significant difference in embryonic development after fertilization. PVP treatment immediately after oolemma rupture significantly decreased the degeneration rate (6.0% vs 19.7%, p = 0.031) and increased the normal fertilization rate. Similarly, there were no significant differences in the developmental potential. Furthermore, pregnancy outcome data showed no significant differences in pregnancy and live birth rates. The degeneration rate was reduced by treating low-stretched oocytes with PVP.Exposure to polyvinylpyrrolidone (PVP) immediately after abnormal membrane rupture represents an effective strategy to prevent oocyte degeneration. This is the first study to propose a strategy for the prevention of oocyte degeneration in Piezo-ICSI. These findings are expected to reduce the oocyte degeneration rate and increase normal fertilization rate as well as assist patients who can only acquire oocytes with weak plasma membranes.

A brief history of technical developments in intracytoplasmic sperm injection (ICSI). Dedicated to the memory of J.M. Cummins

Intracytoplasmic sperm injection (ICSI) is an assisted reproductive technology for treatment of severe male infertility introduced into clinical practice in 1992. This review provides a brief history of the development of ICSI by acknowledging major developments in the field. The review addresses key developments in pre-clinical and early studies, how ICSI compares with in vitro fertilisation, long-term consequences, how the mechanistic approach to ICSI has changed in both manual and semi-automated approaches, and how sperm selection procedures are integrated into ICSI. From the beginnings using animal models in the 1960-1970s, the development of ICSI is a remarkable and transformative success story. Indeed, its broad use (70% of cycles globally) exceeds the need required for treating infertile males, and this remains a controversial issue. There remain questions around the long-term health impacts of ICSI. Furthermore, advances in automation of the ICSI procedure are occurring. An estimated 6million children have been born from the ICSI procedure. With further automation of sperm selection technologies, coupled with automation of the injection procedure, it is likely that the proportion of children born from ICSI will further increase.

Improved fertilization, degeneration, and embryo quality rates with PIEZO-intracytoplasmic sperm injection compared with conventional intracytoplasmic sperm injection: a sibling oocyte split multicenter trial

OBJECTIVE

To investigate whether PIEZO-intracytoplasmic sperm injection (PIEZO-ICSI) increases the fertilization rate, decreases the degeneration rate, and increases the utilization rate per oocyte injected compared with conventional intracytoplasmic sperm injection (ICSI).

DESIGN

Sibling oocyte split multicenter trial.

SETTING

Fertility clinics.

PATIENTS

Women with a diagnosis of infertility who used ICSI as their method of insemination and had ≥6 mature oocytes for injection.

INTERVENTIONS

Participants had their mature oocyte cohort divided, where half were injected using conventional ICSI and the other half were injected using PIEZO-ICSI. For patients with an uneven oocyte number, the extra oocyte was injected using conventional ICSI. The injection technique used first was also randomized to ensure that there was no bias due to order of injection.

MAIN OUTCOME MEASURE

The primary outcome measure was the fertilization rate after injection.

RESULTS

A total of 108 patients underwent a sibling split use of conventional ICSI and PIEZO-ICSI. The fertilization rate was 71.6% in PIEZO-ICSI, which significantly increased compared with that in conventional ICSI 65.6%. In addition, the oocyte degeneration rate decreased in PIEZO-ICSI compared with that in conventional ICSI (6.3% vs. 12.1% respectively), and the blastocyst quality increased, as measured by the number of grade A and B quality blastocysts present on day 5 of development (33.3% vs. 27.5%). No significant differences in the aneuploidy or utilization rate, clinical pregnancy, or live birth outcome after single embryo transfer were noted between the two injection techniques.

CONCLUSIONS

This trial supports the possibility that PIEZO-ICSI increases the fertilization rates, decreases the oocyte degeneration rates, and increases the blastocyst quality compared with conventional ICSI; however, it does not appear to influence the clinical pregnancy or live birth rate per transfer.

CLINICIAN TRIAL REGISTRATION NUMBER

Australian and New Zealand Clinical Trial Registry ACTRN12620000407998.

Identifying optimal puncture position by a real-time image analysis for Piezo-ICSI: a prospective randomized sibling oocyte study

RESEARCH QUESTION

Would the use of the intracytoplasmic sperm injection (ICSI) position detector (IPD) make it possible to identify the optimal puncture position on oolemma during Piezo-ICSI and reduce oocyte degeneration and unintentional membrane rupture (UMR)?

DESIGN

This sibling oocyte study included 917 inseminated oocytes from 113 infertile patients undergoing Piezo-ICSI. Oocytes were randomly divided into two groups: with or without IPD. The rates of UMR, degeneration, fertilization and embryonic development were compared between the two groups. As a secondary analysis, non-IPD oocytes were retrospectively assessed as appropriate or non-appropriate injection sites and analysed alongside prospective 'appropriate' injections.

RESULTS

The rates of UMR (7.0% versus 12.9%, P = 0.004) and degeneration (2.4% versus 6.1%, P < 0.01 = 0.008) were significantly lower in the IPD group than in the non-IPD group. No significant differences, however, were observed in the rates of fertilization (two pronuclei, 83.8% versus 78.9%), blastocyst formation (48.5% versus 48.8%) or good-quality blastocysts (22.5% versus 20.5%). Additionally, no significant differences were observed in the rates of pregnancy (29.4% versus 35.1%) or live births (26.5% versus 29.7%) in a single embryo transfer setting with or without IPD. Comparing all 'appropriate' injections with 'non-appropriate' injections also showed a significantly decreased rate of UMR and degeneration (both P ≤ 0.001).

CONCLUSIONS

The present study demonstrated that a real-time image analysis during Piezo-ICSI markedly reduced oocyte degeneration by avoiding areas associated with a high risk of UMR. Therefore, IPD may increase the number of embryos available for treatment.

Evolution of intracytoplasmic sperm injection: From initial challenges to wider applications

Background

In vitro fertilization (IVF) has revolutionized infertility treatment. Nevertheless, male infertility requires more effective solutions. In 1992, the first-ever case of human birth via intracytoplasmic sperm injection (ICSI) was reported. ICSI involves microscopically injecting a sperm into an ovum. Successful ICSI has become a reliable therapy for couples facing infertility, a significant milestone. However, it has also introduced various challenges. This study also delves into ethical dilemmas arising from widespread ICSI use.

Methods

This review traces the history of ICSI, presenting pioneering attempts, first successful attempts, and critical reports on account of the initial skepticism toward the technology. The review also focuses on chronological progress until ICSI was recognized as effective and became widely applied.

Main findings

The review reveals that ICSI, although transformative, presents challenges. Successes include addressing male infertility and aiding fertilization. However, concerns arise regarding optimal sperm and embryo selection, genetic mutations, and long-term health implications. Ethical considerations surrounding ICSI's broad applications also surface.

Conclusions

Despite its success and effectiveness, ICSI is still evolving as a therapeutic method. By comprehensively evaluating the historical progress and the current status of ICSI and exploring its future prospects, this study highlights the importance of ICSI in infertility treatment.

First babies conceived with Automated Intracytoplasmic Sperm Injection

RESEARCH QUESTION

Can an automated sperm injection robot perform Automated Intracytoplasmic Sperm Injection (ICSIA) for use in human IVF?

DESIGN

The ICSIA robot automated the sperm injection procedure, including injection pipette advancement, zona pellucida and oolemma penetration with piezo pulses, and pipette removal after sperm release. The robot was first tested in mouse, hamster and rabbit oocytes, and subsequently using discarded human oocytes injected with microbeads. A small clinical pilot trial was conducted with donor oocytes to study the feasibility of the robot in a clinical setting. The ICSIA robot was controlled by engineers with no micromanipulation experience. Results were compared with those obtained with manual ICSI conducted by experienced embryologists.

RESULTS

The ICSIA robot demonstrated similar results to the manual procedure in the different animal models tested as well as in the pre-clinical validations conducted in discarded human oocytes. In the clinical validation, 13 out of 14 oocytes injected with ICSIA fertilized correctly versus 16 out of 18 in the manual control; eight developed into good-quality blastocysts versus 12 in the manual control; and four were diagnosed as chromosomally normal versus 10 euploid in the manual control. Three euploid blastocysts from the ICSIA robot group have been transferred into two recipients, which resulted in two singleton pregnancies and two babies born.

CONCLUSIONS

The ICSIA robot showed high proficiency in injecting animal and human oocytes when operated by inexperienced personnel. The preliminary results obtained in this first clinical pilot trial are within key performance indicators.

Imaging the subcellular viscoelastic properties of mouse oocytes

In recent years, cellular biomechanical properties have been investigated as an alternative to morphological assessments for oocyte selection in reproductive science. Despite the high relevance of cell viscoelasticity characterization, the reconstruction of spatially distributed viscoelastic parameter images in such materials remains a major challenge. Here, a framework for mapping viscoelasticity at the subcellular scale is proposed and applied to live mouse oocytes. The strategy relies on the principles of optical microelastography for imaging in combination with the overlapping subzone nonlinear inversion technique for complex-valued shear modulus reconstruction. The three-dimensional nature of the viscoelasticity equations was accommodated by applying an oocyte geometry-based 3D mechanical motion model to the measured wave field. Five domains-nucleolus, nucleus, cytoplasm, perivitelline space, and zona pellucida-could be visually differentiated in both oocyte storage and loss modulus maps, and statistically significant differences were observed between most of these domains in either property reconstruction. The method proposed herein presents excellent potential for biomechanical-based monitoring of oocyte health and complex transformations across lifespan. It also shows appreciable latitude for generalization to cells of arbitrary shape using conventional microscopy equipment.

PIEZO-ICSI increases fertilization rates compared with conventional ICSI in patients with poor prognosis

PURPOSE

Limited research has been published comparing PIEZO-ICSI with conventional ICSI. While positive effects have been documented in improving fertilization and degeneration, the outcomes in patients with previous poor results from conventional ICSI remain unclear. It is hypothesized that these patients may benefit the most from this form of insemination.

METHODS

This retrospective paired within-patient cohort study investigated patients (n=72) undertaking PIEZO-ICSI after a previous conventional ICSI cycle resulted in poor outcomes (including low fertilization (<50%), high degeneration (>15%), and/or poor embryo development and utilization). Patients required at least five oocytes collected in both cycles and a period of less than 2 years between the cycles. The outcomes of both cycles were compared in respect to fertilization, degeneration, embryo utilization, and pregnancy rates. Further analyses were applied to patients <38 and ≥38 years of age, with <50% or ≥50% fertilization with conventional ICSI and with <20% or ≥20% utilization with conventional ICSI.

RESULTS

PIEZO-ICSI resulted in significantly higher fertilization (61.9% vs 45.3%, P<0.0001) and lower degeneration (7.7% vs 18.2%, P=0.0001) when compared to the conventional ICSI cycles. The greatest benefit was seen in patients who had less than 50% fertilization or <20% utilization in their conventional ICSI cycle, with improvements in fertilization and degeneration rates resulting in a significantly higher number of embryos utilized (frozen or transferred) per cycle.

CONCLUSIONS

PIEZO-ICSI improved fertilization, degeneration, and utilization rates in patients with previous poor outcomes from conventional ICSI. The number of embryos available for use per cycle was also increased. Further significant improvements were achieved in patients who exhibited poor fertilization (<50%) or low utilization (<20%) from conventional ICSI.

Comparison of clinical outcomes between conventional in vitro fertilization and intracytoplasmic sperm injection in poor responders with only single oocyte retrieved

OBJECTIVE

To compare the clinical outcomes between conventional insemination (IVF) and intracytoplasmic sperm injection (ICSI) in poor responders with only a single oocyte retrieved.

MATERIALS AND METHODS

This is a retrospective case-control study. Couples who were treated with assisted reproductive technology (ART) with a single oocyte retrieved in Mackay Memorial Hospital from 1996 to 2016 were recruited. All data were categorized into three groups, according to their fertilization method and semen quality: group A, conventional insemination with non-male factor (IVF-NMF, n = 115), group B, ICSI with male factor (ICSI-MF, n = 30), and group C, ICSI with non-male factor (ICSI-NMF, n = 49).

RESULTS

No statistically significant difference was observed between IVF and ICSI groups in pregnancy outcomes, including the chemical or clinical pregnancy rate, miscarriage rate, and live birth rate. Similar fertilization rates per oocyte obtained were observed in IVF and ICSI patients, but significantly lower per mature oocyte in the ICSI group (IVF: 91.5%, ICSI-MF: 75.0%, ICSI-NMF: 77.8%). Although there is no statistical significance, the lower live birth rate is observed in group C than others (A:11.5%, B:25%, C:5%, p = 0.187).

CONCLUSION

In this study, pregnancy outcomes of conventional in vitro fertilization and ICSI in poor responders with only a single oocyte retrieved were similar. However, the fertilization rate of matured oocytes in ICSI groups is significantly lower than that in the IVF group, indicating that ICSI procedures might cause oocyte damage. Therefore, the choice of fertilization method should be based on semen quality. A randomized controlled trial should be performed to confirm our findings.

Value of Meiotic Spindle Imaging on Fertilization and Embryo Development Following Human Oocyte Piezo-ICSI

Background: The objective of this study was to investigate accurately the effect of the meiotic spindle imaging of human oocytes on their fertilization and embryo development by using the Piezo-ICSI.

Methods: We retrospectively assessed 529 oocytes with the first polar body retrieved from 124 infertile couples (147 cycles) who attended our clinic between May 2016 and December 2018. Of these, 489 oocytes (92.4%) with visible meiotic spindle comprised the Spindle (+) group and 40 oocytes (7.6%) not observed meiotic spindle comprised the Spindle (−) group. The meiotic spindle was imaged using polarized light microscopy. The rates of fertilization, high-quality day-3 embryo, day-5 blastocyst, and high-quality day-5 blastocyst were evaluated in both groups.

Results: The fertilization rates of Spindle (+) and Spindle (−) were 92.0% (450/489) and 70.0% (28/40), respectively; high-quality day-3 embryo rates were 62.9% (283/450) and 35.7% (10/28); day-5 blastocyst rates were 53.7% (205/382) and 32.1% (9/28); high-quality day-5 blastocyst rates were 29.8% (114/382) and 3.6% (1/28). Fertilization, high-quality day-3 embryo, day-5 blastocyst, and high-quality day-5 blastocyst rates were significantly higher in the Spindle (+) group than in the Spindle (−) group.

Conclusion: Spindle imaging (i.e., oocytes with a visible meiotic spindle or with not observed meiotic spindle) influences the outcome of Piezo-ICSI in human oocytes, including fertilization and embryo development. To our knowledge, this study is the first to evaluate the effect of meiotic spindle imaging on fertilization or embryo development among oocytes after Piezo-ICSI. The meiotic spindle imaging could be the indicator for the quality management of medical doctors and embryologists.

Relationship between follicular size and developmental capacity of oocytes under controlled ovarian hyperstimulation in assisted reproductive technologies

PURPOSE

We investigate the relationships between oocyte developmental capacity and follicular size of its origin in Japanese women: those undergoing conventional IVF (cIVF) and ICSI, respectively.

METHODS

A total of 3377 follicles were punctured separately and were classified into three groups (large, medium, and small) by their diameters. A total of 1482 retrieved oocytes were individually cultured and received cIVF or ICSI. The oocytes receiving ICSI were denuded and the number of mature (MII) oocytes was counted.

RESULTS

The oocyte retrieval rates and the proportion of MII oocytes were significantly lower in small follicles than in large follicles. Under cIVF, the fertilization rate was significantly lower in oocytes from small follicles than large follicles. Under ICSI, the fertilization rate for MII oocytes was not significantly related to follicular size. Follicular size was not significantly related to the development potential to blastocyst and pregnancy rate for either the cIVF oocytes or the ICSI oocytes.

CONCLUSIONS

Although the fertilization rate by cIVF is low in oocytes from small follicles due to the lower proportion of mature oocytes, their development potential is comparable to that of oocytes from larger follicles if they could be fertilized. Under ICSI using mature oocytes, their development potential is not related to follicular size.

PIEZO-ICSI increases fertilization rates compared with standard ICSI: a prospective cohort study

RESEARCH QUESTION

Is PIEZO-intracytoplasmic sperm injection (ICSI) coupled with a new novel operational fluid (perfluoro-n-octane) superior to standard ICSI?

DESIGN

A cohort of patients (n = 69) undertaking microinjection were recruited between January and November 2019 and were then prospectively case-matched. Patients required six or more mature oocytes for inclusion in the study. PIEZO-ICSI uses high-speed microinjection drilling to penetrate the zona and oolemma and deposit the spermatozoa into the cytoplasm, compared with the traditional 'cutting' action of ICSI. The primary outcome was fertilization, with secondary outcomes including oocyte degeneration, abnormal fertilization, embryo cryopreservation and embryo utilization.

RESULTS

PIEZO-ICSI resulted in significantly higher fertilization rates (80.5 ± 2.4% vs 65.8 ± 2.3%, P < 0.0001) and lower oocyte degeneration rates (4.4 ± 1.3% vs 8.6 ± 1.2%, P = 0.019) and abnormal fertilization rates (2.9 ± 1.1% vs 7.4 ± 1.1%; P = 0.003) compared with standard ICSI. This improvement in fertilization was of most benefit in patients aged ≥38 years. This increase in fertilization increased the number of good quality embryos that were available for cryopreservation/transfer (3.8 ± 0.2 vs 3.1 ± 0.2; P = 0.038), such that patients on average had one extra usable embryo per cycle compared with standard ICSI. There were no differences to Day 5 embryo development or clinical pregnancy from fresh embryo transfer (57.1% PIEZO-ICSI vs 60.0% ICSI) between microinjection methods, although pregnancy outcomes were underpowered.

CONCLUSIONS

PIEZO-ICSI significantly increased fertilization rates, thereby increasing the number of embryos available for cryopreservation compared with standard ICSI. Further prospective studies assessing cumulative pregnancy rates are warranted.

Laser-assisted hatching on clinical and neonatal outcomes in patients undergoing single vitrified Blastocyst transfer: A propensity score-matched study

PURPOSE

This study determined the effect of laser-assisted hatching on the clinical and neonatal outcomes of single vitrified blastocyst transfer.

METHODS

From June 2014 to March 2018, 289 matched pairs after propensity score matching were analyzed. During the blastocyst warming procedure, a small section of the zona pellucida area in the empty perivitelline space was sliced off using multiple laser beams. The clinical and neonatal outcomes of the laser-treated group and non-treatment control were analyzed.

RESULTS

In the laser-assisted hatching group, significantly higher rates of clinical pregnancy (40.8% vs 29.4%, P < .01) and live delivery (34.3% vs 22.5%, P < .01) were observed compared to the control group. Other variables such as the average gestational weeks, the sex of the baby, birthweight, or congenital malformations were found to have no significant differences in neonatal outcomes. Moreover, all babies were singleton live births.

CONCLUSIONS

Single vitrified blastocyst transfer treated with laser-assisted hatching increases the live birth rate and has no adverse effects on neonatal outcomes.

ICSI Does Not Improve Live Birth Rates but Yields Higher Cancellation Rates Than Conventional IVF in Unexplained Infertility

Objectives: Unexplained infertility has been one of the indications for utilization of intracytoplasmic sperm injection (ICSI). However, whether ICSI should be preferred to IVF for patients with unexplained infertility remains an open question. This study aims to determine if ICSI improves the clinical outcomes over conventional in vitro fertilization (IVF) in couples with unexplained infertility.

Methods: This was a retrospective cohort study of 549 IVF and 241 ICSI cycles for patients with unexplained infertility at a fertility center of a university hospital from January 2016 and December 2018. The live birth rate and clinical pregnancy rate were compared between the two groups. Other outcome measures included the implantation rate, miscarriage rate, and fertilization rate.

Results: The live birth rate was 35.2% (172/488) in the IVF group and 33.3% (65/195) in ICSI group, P = 0.635. The two groups also had similar clinical pregnancy rates, implantation rates, and miscarriage rates. The fertilization rate of IVF group was significantly higher than that of ICSI group (53.8 vs. 45.7%, P = 0.000, respectively). Sixty-one and 46 patients did not transfer fresh embryos in IVF and ICSI cycles, respectively. Patients with IVF cycles had lower cancellation rates than those with ICSI (11.1 vs. 19.1%, P = 0.003, respectively).

Conclusion: ICSI does not improve live birth rates but yields higher cancellation rates than conventional IVF in the treatment of unexplained infertility.

Effect of equilibration time on clinical and neonatal outcomes in human blastocysts vitrification

PURPOSE

Prolonged exposure to equilibration solutions may be detrimental to an embryo's developmental potential, whereas a shorter exposure may affect the penetration of cryoprotectants into blastomeres. The purpose of this study was to evaluate the effects of different equilibration times on the clinical and neonatal outcomes of human blastocyst vitrification.

METHODS

This is a retrospective study based on data collected between November 2008 and November 2015. A total of 192 blastocysts (80 non-expanded and 112 expanded) obtained from 167 patients were analyzed. The blastocysts were divided into two groups according to their equilibration time: 8-11 minutes or 12-15 minutes. The clinical and neonatal outcomes of warmed blastocysts were evaluated.

RESULTS

The survival, implantation, and live birth rates of non-expanded blastocysts were not different between the two groups, but they significantly improved for the expanded blastocysts in the 12-15 minutes group compared to the 8-11 minutes group. The results were similar for the neonatal outcomes after vitrified embryo transfer, when partitioned by equilibration time and blastocyst stage at vitrification.

CONCLUSIONS

For the non-expanded blastocysts, a shortened equilibration time (8-11 minutes) is sufficient for effective vitrification.