The relationship between age and rates of abnormal fertilization following intracytoplasmic sperm injection (ICSI)

2020 ◽  
Vol 41 ◽  
pp. e8
Author(s):  
B. Hanson ◽  
J. Kim ◽  
A. Tiegs ◽  
E. Osman ◽  
K. Hong ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Abnormal Fertilization ◽  
The Relationship

142 POSSIBLE BENEFIT OF INTRACYTOPLASMIC SPERM INJECTION ON THE EFFICIENCY OF EMBRYO PRODUCTION IN AGED COWS

2017 ◽  
Vol 29 (1) ◽  
pp. 179
Author(s):  
F. Magata ◽  
K. Tsuchiya ◽  
H. Komaki ◽  
M. Konishi ◽  
A. Ideta
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Blastocyst Stage ◽  
Cortical Granule ◽  
Cortical Granules ◽  
Embryo Production ◽  
Fertilization Rates ◽  
Abnormal Fertilization ◽  
Cytoplasmic Maturation ◽  
Maternal Aging ◽  
Bovine Oocytes

Reduction in oocyte quality is a major factor responsible for declining fertility with age. The abnormal fertilization rate of oocytes from aged cows was reportedly higher than that of oocytes from young cows (Iwata et al. 2011. Reprod. Fertil. Dev. 23, 424–432). We hypothesised that assisted fertilization by intracytoplasmic sperm injection (ICSI) might improve the developmental abilities of oocytes collected from aged females. The aims of the study were (1) to determine the effect of maternal aging on the ability of bovine oocytes to undergo cytoplasmic maturation, fertilization, and further embryo development; and (2) to determine whether ICSI would improve the efficiency of embryo production in aged cows. Cows aged 30 to 50 months or >120 months were defined as young or aged, respectively. Cumulus-oocyte complexes were harvested from abattoir-derived ovaries of young (40 ± 7 months, n = 89) and aged (136 ± 12 months, n = 55) Holstein cows and matured for 23 h in TCM-199 supplemented with 5% fetal bovine serum (FBS) at 38.5°C under 5% CO2 with saturated humidity. Then, surrounding cumulus cells were removed, and cortical granules in the oocyte were stained with Lens culinaris–fluorescein isothiocyanate to evaluate the cytoplasmic maturation. Matured oocytes were inseminated by IVF or ICSI. At 15 h post-insemination, the numbers of pronuclei were determined to evaluate the fertilization rates. Presumptive IVF- or ICSI-derived zygotes were cultured for 5 days in CR1aa medium with 2% FBS and subsequently in USU6 with 5% FBS for 3 days at 38.5°C in 5% O2, 5% CO2, and 90% N2 with saturated humidity. Chromosome numbers of blastocysts were counted to evaluate the effect of maternal aging on ploidy. All experiments were performed with more than 4 independent runs, and data were analysed using chi-square tests. The distribution of matured oocytes into different cortical granule classes was affected by age, with a significantly lower (P < 0.01) proportion of class III (mature cytoplasm) oocytes from aged cows (29%) compared with those from young cows (57%). Although fertilization rates following IVF did not differ between the groups, the proportion of abnormal fertilization (more than 2 pronuclei) was 32% in the aged group: higher than in the young group (15%; P < 0.01). The rates of cleaved embryos following IVF were the same among groups, but the rate of development to the blastocyst stage of oocytes from aged cows (38%) was significantly (P < 0.05) lower than in those from young cows (52%). Moreover, the proportion of diploid blastocysts with 2 sets of chromosomes (2n = 60) was lower (47%) in the aged than in the young groups (75%; P < 0.05). However, in the ICSI embryos, the rates of development to the blastocyst stage did not differ significantly between groups (young 36%; aged 43%). Thus, maternal aging might impair the cytoplasmic maturation of bovine oocytes, which could be associated with abnormal fertilization or low developmental competence. Our results also indicate possible beneficial effects of ICSI on the efficiency of embryo production in aged cows.

scholarly journals Fertilization failures and abnormal fertilization after intracytoplasmic sperm injection

1998 ◽  
Vol 13 (suppl 1) ◽  
pp. 155-164 ◽  
Author(s):  
S. P. Flaherty ◽  
D. Payne ◽  
C. D. Matthews
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Abnormal Fertilization

scholarly journals Comet assay of cumulus cell DNA status and the relationship to oocyte fertilization via intracytoplasmic sperm injection*

2001 ◽  
Vol 16 (5) ◽  
pp. 831-835 ◽  
Author(s):  
Rita S. Raman ◽  
Philip J. Chan ◽  
Johannah U. Corselli ◽  
William C. Patton ◽  
John D. Jacobson ◽  
...  
Keyword(s):  
Comet Assay ◽  
Intracytoplasmic Sperm Injection ◽  
Cumulus Cell ◽  
Oocyte Fertilization ◽  
The Relationship

Assessment of fertilization failure and abnormal fertilization after intracytoplasmic sperm injection (ICSI)

1995 ◽  
Vol 7 (2) ◽  
pp. 197 ◽  
Author(s):  
SP Flaherty ◽  
D Payne ◽  
NJ Swann ◽  
CD Matthews
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Polar Body ◽  
Sperm Head ◽  
Oocyte Activation ◽  
Fertilization Failure ◽  
Metaphase Chromosomes ◽  
Polar Bodies ◽  
Abnormal Fertilization ◽  
Second Polar Body ◽  
Sperm Chromosomes

The assessment of fertilization is an important part of intracytoplasmic sperm injection (ICSI) and oocytes are routinely examined about 17 h after injection using Nomarski differential interference contrast optics. However, it is not possible to conclusively determine the aetiology of fertilization anomalies in this manner, so cytological studies were undertaken to determine the causes of failed and abnormal fertilization after ICSI. Oocytes which exhibited no evidence of fertilization, one pronucleus (PN) or 3 PN were fixed in glutaraldehyde, stained with Hoechst 33342 and examined by fluorescence microscopy to identify PN, metaphase chromosomes, sperm heads and polar bodies. A total of 428 unfertilized oocytes were examined from 170 ICSI cycles. Overall, 82% of these unfertilized oocytes were still at metaphase II (non-activated) while the remaining 18% were activated and had 1 PN and two polar bodies. The majority (71%) of the metaphase II oocytes contained a swollen sperm head, which indicates that the spermatozoon was correctly injected but the oocyte did not activate and complete its second meiotic division. The swollen sperm head was located among the metaphase chromosomes in 4.3% of these oocytes, while in some cases (6.6%), the sperm chromosomes had undergone premature chromosome condensation (PCC). Other aetiologies of failed fertilization in these metaphase oocytes were ejection of the spermatozoon from the oocyte (19%) and complete failure of sperm head decondensation (10%). A similar pattern of anomalies was found in 1 PN oocytes, although the ratios were different (swollen sperm head, 51%; ejection of the spermatozoon, 19%; undecondensed sperm head, 30%). Seventy abnormally fertilized oocytes were also examined, of which 63 had 3 PN and a single polar body, indicating that the unextruded second polar body developed into the third PN. In conclusion, the present study demonstrates that the principal cause of fertilization failure after ICSI is failure of oocyte activation and not ejection of the spermatozoon from the oocyte. It is also apparent that further studies are needed to elucidate the mechanisms that control oocyte activation and sperm head decondensation in injected oocytes.

P–192 Efficacy of postponement of intracytoplasmic sperm injection timing after spindle visualization for Metaphase I oocytes

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
N Hisa ◽  
H Ito ◽  
R Kotake ◽  
S Akimoto ◽  
Y Suzuki ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Developmental Outcomes ◽  
Control Group ◽  
Blastocyst Formation ◽  
Immature Oocytes ◽  
Fertilization Rates ◽  
Abnormal Fertilization ◽  
Group A ◽  
Cytoplasmic Maturation ◽  
Group B

Abstract Study question Does postponement of intracytoplasmic sperm injection (ICSI) timing after spindle visualization for Metaphase I (MI) oocytes improve developmental outcomes of embryos? Summary answer Postponement of ICSI timing after spindle visualization for MI oocytes improves blastocyst utility rates. What is known already Immature oocytes are generally considered poor developmental outcomes. Meanwhile, the timing of ICSI adjusted by using spindle visualization can improve clinically utilized embryos and live birth rates, but these outcomes remain inferior to those of mature oocytes. In in vitro maturation culture, nuclear maturation is thought to occur before the completion of cytoplasmic maturation, and in immature oocytes, synchronization of nuclear and cytoplasmic maturation may be insufficient for ICSI immediately after spindle visualization. Study design, size, duration Data for this retrospective cohort study were obtained 672 oocytes retrieved under mild stimulation cycles using letrozole, in patients aged younger than 39 years between April 2017 and October 2020.Written informed consent was obtained from all patients. This study was approved by the institutional review board. Participants/materials, setting, methods As a control group, 464 MetaphaseIIoocytes that underwent ICSI immediately after visualization of the spindle were used. In group A, 103 MI oocytes underwent ICSI immediately after the first polar body release and spindle visualization, and in group B, 105 oocytes underwent ICSI 2–3 hours after spindle visualization. The primary outcomes were fertilization rates, degeneration, cleavage, embryo blastocyst formation, and utility rates. Outcomes were compared among the three groups. Main results and the role of chance The baseline fertilization rates of each group (control, A, B) were 82.3% (382/464), 73.8% (76/103), and 83.8% (88/105), respectively. The rate was significantly lower in group A than in the control group (P &lt; 0.05), and also tended to be lower in group A than in group B, although the difference was not significant. There was no significant difference in abnormal fertilization rates, oocyte degeneration rates, cleavage rates, and blastocyst formation rates among the three groups. [control, A, B: abnormal fertilization rate: 4.3% (20/464), 8.7% (9/103), 4.8% (5/105); oocyte degeneration rates: 3.0% (14/464), 1.9% (2/103), 3.8% (4/105); cleavage rates: 95.6% (307/321), 93.8% (61/65), 98.7% (74/75); blastocyst formation rates: 58.6% (177/302), 51.7% (31/60), 55.4% (41/74), respectively]. The blastocyst utility rates of control group and group B were significantly higher than in group A [41.7% (126/302), 45.9% (34/74), 26.7% (16/60), respectively] (P &lt; 0.05). There were no significantly different outcomes between the control group and group B. Limitations, reasons for caution The optimal timing of ICSI for MI oocyte cannot be determined by the presence or absence of spindles. In addition, the postponement duration we set was based on reports which reported on final oocyte maturation, and further investigation is needed to establish the optimal ICSI timing for MI oocytes. Wider implications of the findings: In MI oocytes, postponement of ICSI timing after spindle visualization is essential for synchronization of the nucleus and cytoplasmic maturation. Trial registration number none

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