Sperm chromatin maturity and integrity correlated to zygote development in ICSI program

Abstract

This study aimed to evaluate sperm chromatin maturity and integrity of that injected into goodquality oocytes in an in vitro fertilization-intra cytoplasmic sperm injection (IVF-ICSI) program. A cut-off value of sperm chromatin maturity and integrity was developed as a function of their correlation to the zygote development, i.e., embryo formation and cleavage rate. The study assessed sperm chromatin maturity using aniline blue (AB) staining, whereas toluidine blue (TB) staining was used to assess sperm chromatin integrity. Ejaculates from 59 patients undergoing ICSI and 46 fertile normozoospermic donors for determination of normal values of sperm chromatin status were used in this study. Embryo formation and cleavage rates were observed for the period of 3 days after ICSI. There was a significant difference in the percentage of sperm with mature chromatin between ejaculate from ICSI patients and fertile donor (p=0.020); while there was no significant difference in sperm chromatin integrity of both samples (p=0.120). There was no significant correlation between sperm chromatin maturity and either embryo formation or cleavage rate; as well as sperm chromatin integrity to both parameters of zygote development (p>0.05). Furthermore, we found that the cut-off value of sperm chromatin maturity and integrity of the fertile normozoospermic ejaculates were 87.2% and 80.2%, respectively. Using the cut-offs, we found that low sperm chromatin maturity at the level of <87% correlated significantly with the cleavage rate of the zygote (p=0.022; r=0.371); whereas poor sperm chromatin integrity at the level of <80% correlated with embryo formation (p=0.048; r=0,485). In conclusion, this study showed that poor maturity and integrity of sperm chromatin (AB<87% and TB<80%, respectively), could affect zygote development following ICSI.

Paternal factors contributing to embryo quality

“…An increased percentage of sperm with immature chromatin [as judged by its structure, condensation, and integrity] has been associated with lower fertilization rate and slower embryo development [42]. Sperm chromatin maturity has also been shown to play a pivotal role in the accomplishment of a pregnancy [43]; a chromatin maturity at the level of AB < 87% correlated significantly with the cleavage rate of the zygote [p = 0.022; r = 0.371] and chromatin integrity at the level of TB < 80% correlated with embryo formation [p = 0.048; r = 0,485] [44]. Another variation of sperm chromatin abnormality characterized by atypical packing of chromosome territories in sperm, aberrant positioning of chromosomes, or disturbed telomere-centromere interactions has also been reported in some infertile males and it is suggested that this abnormality may impact embryonic development [45].…”

Fatherhood and Sperm DNA Damage in Testicular Cancer Patients

“…Most studies using TUNEL reported a significant impact on embryo development, blastocysts and pregnancy loss for both IVF and ICSI, whereas studies using SCSA obtained more variable results ( 57 ). This may be because the different methods identify different aspects of DNA damage: in fact, the alkaline Comet and TUNEL assays can directly measure the level of sperm DNA damage, while SCSA indirectly measures the susceptibility of DNA to damage, consequently influencing the discovered associations with ART outcome ( 58 , 59 ).…”

Impact of chromatin condensation assessment by aniline blue test on seminal parameters and outcomes in egg donation program

“…Our study used OD cycles as a model to better understand male impact and focused the attention on semen parameters, age, BMI and that could be a potential index of male infertility. AB test ≥ 19% were more associated with men with abnormal concentration and motility (oligoasthenozoospermic) and this could be due to a different spermatogenic remodeling of chromatin resulting in greater histone retention (>15%) or chromatin non-condensation [38,42,43]. To evaluate the influence of AB test cut-off of 19% on clinical outcomes, we considered OD cycles in which female factor (maternal age) has a heavy weight on the results [44].…”

“…On the day of insemination, all subjects underwent semen analysis: fresh semen was collected in a sterile jar by masturbation after 3-5 days of sexual abstinence. Semen analysis has been performed following the WHO 2010 [28] at 5° percentile: semen volume, 1,5 (1,4-1,7) ml; total sperm number, 39 (33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46) million per ejaculate, sperm concentration, 15 (12-16) million per ml; progressive motility, 32% (31)(32)(33)(34); total (progressive, non-progressive) motility, 40% (38)(39)(40)(41)(42); morphology 4,0% (3,0-4,0). Swim-up was performed for semen preparation.…”