Intracytoplasmic single sperm injection: preclinical training and first clinical results

Are we ready to inject? Individualized LC-CUSUM training in ICSI

PURPOSE

The objective of this prospective, single center study was to develop a personalized training scheme for intracytoplasmic sperm injection (ICSI) through the use of learning curve-cumulative summation (LC-CUSUM), which allows to tailor training to the trainee performance, and to validate it against the performance of experienced embryologists.

METHODS

Five trainees microinjected latex microspheres (LM) into vitro matured oocytes. A microinjection was considered successful when the oocyte did not lyse in the 24 h following the injection.

RESULTS

Each trainee became proficient at ICSI after a variable number of injections, ranging from 35 to 80. Trainees that achieved proficiency went on to perform ICSI with human gametes in a clinical setting with proficiency comparable to that of experienced embryologists.

CONCLUSIONS

We show that LC-CUSUM based personalized ICSI training is feasible and allows trainees to be as proficient as trained embryologists when treating actual patients.

Short-term medical complications of 1500 oocyte retrievals for in vitro fertilization and embryo transfer

OBJECTIVE

To evaluate the different short-term complications after in vitro fertilization and embryo transfer.

DESIGN

a retrospective study on 7 years in the fertility clinic of an university hospital.

MATERIALS AND METHODS

Short-term medical complications were analysed after 1500 transvaginal ultrasonographically guided oocyte retrievals.

RESULTS

Ovarian hyperstimulation syndrome (1.8%), pelvic infections (0.4%), intraperitoneal bleeding (0.2%) and adnexal torsions (0.13%) were observed. One case of adnexal torsion occurred during pregnancy (0.18%). Two unusual case of bowel endometriosis were encountered (0.13%).

CONCLUSIONS

Short-term medical complications after in vitro fertilization and embryo transfer are rare (2.8%). This contrast with the high rate of multifetal pregnancies which increases maternal and perinatal morbidity and mortality and must be considered as the major complication of in vitro fertilization treatment.

Technical and physiological aspects associated with the lower fertilization following intra cytoplasmic sperm injection (ICSI) in human

The fertilization rates with ICSI range from 30% to 70% and suggest that, despite injecting sperm into mature oocytes, significant fertilization failure still occurs in humans. The objective of this study was to determine technical and physiological factors which may contribute to lower fertilization following ICSI. Eggs that failed to show two pronuclei (PN) 48 hours after ICSI were studied at two different time intervals: at ICSI program inception (group A) and after 8 months (group B). The eggs were analyzed by staining with DNA fluorochromes, Hoescht 33258 and DAPI. The extent of sperm head as well as maternal chromatin decondensation in unfertilized ICSI eggs was determined by high resolution fluorescence microscopy. The average fertilization rate (FR) from all ICSI cycles in these two groups was 45%. The FR in Groups A and B were 35% and 59%, respectively (P < 0.05). In Group A, 65% of the unfertilized eggs were characterized by condensed sperm chromatin with 11% showing partial decondensation. In Group B, only 28% of the unfertilized eggs demonstrated condensed sperm chromatin while 45% were partially decondensed. Sperm chromatin was not detected in 24% of all unfertilized eggs studied. The maternal chromatin remained at metaphase II in 84% of all unfertilized eggs analyzed. These observations suggest that the technical problem of deposition of the sperm inside the egg is not the major cause for failure of fertilization rates in ICSI cycles. The increased percentage of eggs undergoing sperm head decondensation may be related to subtle changes in technique as experience is gained over time. The failure of sperm head decondensation in some of the ICSI eggs may be associated with cytoplasmic immaturity but not nuclear maturity.

Failed fertilization after intracytoplasmic sperm injection: the extent of paternal and maternal chromatin decondensation

OBJECTIVE

To determine the extent of paternal and maternal chromatin decondensation in unfertilized eggs after intracytoplasmic sperm injection (ICSI).

DESIGN

Eggs that failed to show two pronuclei (2-PN) 48 hours after ICSI were studied at two different time intervals: at ICSI program inception (group A) and after 8 months (group B).

PATIENT(S)

Forty-nine patients undergoing IVF cycles.

MAIN OUTCOME MEASURE(S)

The unfertilized eggs were studied by chromatin staining.

RESULT(S)

The average fertilization rate from all ICSI cycles in these two groups was 45%. The fertilization rates in groups A and B were 35% and 59%, respectively. In group A, 65% of the unfertilized eggs were characterized by condensed sperm chromatin with 11% showing partial decondensation. In group B, only 28% of the unfertilized eggs demonstrated condensed sperm chromatin, whereas 45% were partially decondensed. In these two groups, no sperm chromatin was detected in 24% of the unfertilized eggs. The maternal chromatin remained at metaphase II in 84% of all unfertilized eggs analyzed.

CONCLUSION(S)

These observations suggest that the technical problem of deposition of the sperm inside the egg is not the major cause of failure of fertilization rates in ICSI cycles. Rather, it is likely to be the failure to complete both the maternal and paternal chromatin transitions that occur with normal fertilization.

Clinical review 87: In vitro fertilization for male factor infertility

Since the first U.S. report of a successful delivery from in vitro fertilization in 1982 (65), progress in the field of assisted reproduction and micromanipulation has been truly dramatic. Perhaps the most exciting advances have been in the area of male factor infertility. Couples who previously would have been offered donor insemination or adoption are now achieving pregnancies despite severe impairments in semen quality, the presence of only single numbers of sperm in the ejaculate, or unreconstructable reproductive tract obstruction. Techniques of micromanipulation that were revolutionary less than five yr ago are now obsolete, replaced by even more successful methods. Even nonobstructive azoospermia resulting from maturation arrest or other impairments in germ cell development have been added to the list of treatable factors in male infertility, as sperm can frequently be extracted directly from testicular parenchyma that is aspirated or surgically biopsied. For patients without sperm in the testicular parenchyma, round spermatid or secondary spermatocyte injections are at least theoretically possible. Several important questions remain with regard to IVF-ICSI. 1) What should be the specific indications for IVF and IVF-ICSI? Should IVF alone ever be used for male factor infertility? 2) What are the reasons for failure to achieve pregnancy after ICSI, which still represent over half of our attempts at achieving ongoing pregnancies? 3) Can we be certain that using severely impaired or less mature sperm will not result in significant birth defects or in genetic abnormalities that could affect the offspring in adolescence or adulthood? 4) What is the most successful and cost effective approach for the infertile couple with impaired semen parameters? For couples with male factor infertility, careful evaluation and treatment of the man should be considered before assisted reproduction, including ICSI. Contemporary application of ICSI for severe male factor infertility can allow pregnancy rates up to 52% (33), with ongoing pregnancy and live delivery rates as high as 37% per IVF cycle attempt (27). As long as viable sperm are present in the ejaculate or retrievable from the reproductive tract, then ICSI procedures can be applied.

The use of piezo micromanipulation for intracytoplasmic sperm injection of human oocytes

INTRODUCTION

This paper describes the use of piezo actuator technology for intracytoplasmic sperm injection of human eggs.

METHODS

Piezo micromanipulation involves a simple and easily made injection pipette of very thin diameter and wall thickness, and it has recently been developed using a mouse model. No bevel or spike is required on the pipettes used. The piezo actuator attaches to conventional micromanipulators and acts to mechanically advance the pipette tip through the zona pellucida using a piezoelectric effect. The oolemma could, in some cases, also be broken using piezo. This technique was applied to 39 patients presenting for in vitro fertilization due to male-factor infertility.

RESULTS

The fertilization rate of eggs injected (60.5%), damage rate (7.6%), abnormality rate (3%), and ongoing pregnancy rate beyond 8 weeks (28.2%) are comparable to those for other techniques that have been successfully reported.

Second polar body extrusion is highly predictive for oocyte fertilization as soon as 3 hr after intracytoplasmic sperm injection (ICSI)

OBJECTIVE

Our objective was to evaluate the time course and the predictive value of the extrusion of the second polar body after intracytoplasmic injection (ICSI) related to the fertilization rate, embryo cleavage and quality.

SETTING

The setting was the in vitro fertilization program of a university hospital.

PATIENTS

Twenty-one patients were treated with intracytoplasmic single sperm injection either for fertilization failure in IVF, low fertilization in IVF (< 5%), or severe male factors.

DESIGN

One hundred thirty-five of 205 metaphase 2 oocytes treated with intracytoplasmic single sperm injection were observed 1, 2, and 3 hr after the assisted fertilization procedure. Extrusion of the second polar body was recorded. For each of these oocytes, fertilization was noted 18 hr after ICSI and cleavage and embryo quality were assessed 24 hr later. The 70 remaining oocytes were used to assess a possible negative effect of repeated exposure to light microscopy.

RESULTS

The extrusion of the second polar body 3 hr after injection was an observation with a sensitivity of 0.87, a specificity of 0.58, and a high positive predictive value (0.90) toward oocyte fertilization. Twenty-nine and four-tenths percent of the oocytes extruded a second polar body within the first hour, 56.6% within the first 2 hr, and 78.3% had a second polar body 3 hr after injection. This time course was related neither to the speed of embryo cleavage nor to the embryo quality. Fertilization, cleavage, and embryo quality were not affected by repeated observation as deduced from comparison with the control group and confirmed by a high pregnancy (62% per oocyte retrieval) and implantation rate (22% per replaced embryo).

CONCLUSION

Oocytes can be checked, in all safety, 3 hr after a single sperm injection for the presence of a second polar to predict oocyte fertilization with a high certainty.