Impact of sperm genome decay on Day-3 embryo chromosomal abnormalities from advanced-maternal-age patients

High sperm DNA fragmentation increased embryo aneuploidy rate in patients undergoing preimplantation genetic testing

RESEARCH QUESTION

Is high sperm DNA fragmentation (SDF) associated with a high embryonic aneuploidy rate in patients undergoing intracytoplasmic sperm injection (ICSI)-preimplantation genetic testing (PGT)?

DESIGN

This was a retrospective study of 426 couples with normal karyotypes undergoing ICSI-PGT at the authors' centre from March 2017 to March 2021. SDF was assessed using the sperm chromatin structure assay. The population was divided into low and high SDF groups according to cut-off values found by the receiver operating characteristic (ROC) curve. A 1:1 ratio propensity score matching (PSM) method was used to control for potential confounding factors, and a generalized linear mixed model was established to evaluate the relationship between SDF and the embryonic aneuploidy rate.

RESULTS

The ROC curve indicated a threshold of 30%. In total, 132 couples were included after PSM, and the high SDF group (>30%) had significantly higher SDF (40.74% ± 9.78% versus 15.54% ± 7.86%, P < 0.001) and a higher embryo aneuploidy rate (69.36% versus 53.96%, P < 0.001) compared with the low SDF group (≤30%). The two pronuclear fertilization rate, cleavage rate, rate of high-quality embryos at day 3 rate, blastocyst rate, biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate, live birth rate, caesarean section rate, preterm birth rate, singleton rate and low birthweight rate were similar in both groups (P > 0.05). After PSM, SDF > 30% was significantly correlated with an increased embryo aneuploidy rate after adjusting for all confounding variables (adjusted odds ratio 1.70, 95% CI 1.00-2.88, P = 0.049).

CONCLUSIONS

SDF > 30% was associated with an increased embryo aneuploidy rate in couples with normal karyotypes undergoing PGT, but did not affect embryonic and clinical outcomes after transfer of euploid embryos.

Paternal Age Matters: Association with Sperm Criteria's- Spermatozoa DNA Integrity and Methylation Profile

Advanced age has been reported to negatively affect sperm parameters and spermatozoa DNA integrity. A decline in sperm criteria was also associated with altered epigenetic marks such as DNA methylation with a potential downstream impact on in vitro fertilization success and clinical outcomes. The aim of the present retrospective study was to clarify the association between advanced paternal age (APA) and sperm parameters, DNA integrity and DNA methylation profile. A total of 671 patients consulting for infertility underwent sperm analysis, sperm DNA integrity assessment and methylation level measurement. The principal finding was that individuals over 40 years of age exhibit a significant increase in DNA fragmentation levels compared to the younger group (15% versus 9%, respectively, p = 0.04). However, there was no significant difference in DNA decondensation and sperm parameters in association with APA. In addition, a drop in the global methylation level was also found in men over 40 years (6% in the young group versus 2% in the old group, p = 0.03). As a conclusion, men over 40 years are at higher risk of elevated sperm DNA fragmentation and lower methylation level. Based on these observations, it is recommended that the assessment of sperm DNA fragmentation should be taken into consideration particularly after the age of 40. Our findings support the idea that paternal age is a crucial factor that should not be neglected during fertility evaluation and treatment since it is associated with epigenetics changes in sperm. Although the underlying mechanism remains to be clarified, we believe that environmental and professional exposure factors are likely involved in the process.

Sperm deoxyribonucleic acid fragmentation index at the time of intracytoplasmic sperm injection and standard in vitro fertilization is correlated with lower fertilization but not with blastocyst genetic diagnosis

Objective

To determine the effects of sperm deoxyribonucleic acid (DNA) fragmentation at the time of fertilization on in vitro fertilization (IVF) outcomes and genetic diagnosis using next generation sequencing.

Design

Prospective double-blinded study.

Setting

Private Clinic.

Patients

Couples (n = 150).

Intervention

In vitro fertilization with preimplantation genetic testing for aneuploidy and sperm DNA fragmentation assay, as in sperm chromatin structure assay the day of retrieval.

Main Outcome Measures

Laboratory outcomes are listed in the results section. Statistical analysis was performed using JMP, XYLSTAT, and STATA version 15.

Results

The sperm DNA fragmentation index (DFI) in the neat ejaculate did not predict fertilization rate, quality, blastulation, or genetic diagnosis. No statistically significant results were obtained comparing <15% with >15%, <20% with >20%, <30% with >30% except for DFI. No statistically significant differences in oocyte source age or male age were observed. No statistically significant differences comparing <15% with >15%, <20% with >20%, <30% with >30% DFI at the time of standard IVF or intracytoplasmic sperm injection (ICSI) were observed for % euploid, aneuploid, mosaic, blastulation, biopsied, or D5/total biopsied. The DFI of >15% had more good quality D3 embryos than the <15% group, as did the >20% group compared with the <20% group. The ICSI fertilization was significantly higher in all 3 lower percentage groups compared with the higher counterpart. Standard IVF had significantly more blastocysts/fertilized suitable for biopsy and more D5/total number biopsied than ICSI embryos despite no difference in DFI.

Conclusions

The DFI at fertilization is correlated with decreased fertilization for ICSI and IVF.

Is there a correlation between paternal age and aneuploidy rate? An analysis of 3,118 embryos derived from young egg donors

OBJECTIVE

To investigate a possible correlation between chromosomal aberrations and paternal age, analyzing embryos derived from young oocyte donors, with available preimplantation genetic testing for aneuploidy results from day 5/6 trophectoderm biopsy obtained by next-generation sequencing for all 24 chromosomes.

DESIGN

Retrospective cohort study.

SETTING

Canadian fertility centre.

PATIENT(S)

A total of 3,118 embryos from 407 male patients, allocated into three paternal age groups: group A, ≤39 years (n = 203); group B, 40-49 years (n = 161); group C, ≥50 years (n = 43).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The primary outcomes were aneuploidy, euploidy, mosaicism, and blastocyst formation rates. Secondary endpoints were comparison of specific chromosome aneuploidy, segmental and complex (involving two chromosomes + mosaicism >50%) aneuploidy, and analysis of overall percentage of chromosomal gains and losses within each group.

RESULT(S)

The study included 437 in vitro fertilization (IVF) antagonist cycles using 302 oocyte donors in which preimplantation genetic testing for aneuploidy was performed. Overall, 70.04% of embryos were euploid, 13.9% were aneuploid, and 16.06% were mosaic. No significant differences among paternal age groups A, B, and C were found in euploidy rates (69.2%, 70.6%, 71.4%, respectively), aneuploidy rates (14.7%, 12.8%, 13.9%, respectively) or mosaicism rates (16.1%, 16.6%, 13.6%; respectively). The fertilization rate was lower in group C compared with group B (76.35% vs. 80.09%). No difference was found in blastocyst formation rate between the study groups (median 52% [interquartile range, 41%, 67%] vs. 53% [42%, 65%] vs. 52% [42%, 64%], respectively). A generalized linear mixed model regression analysis for embryo ploidy rates found older oocyte donor age to be independently associated with embryo aneuploidy (odds ratio = 1.041; 95% CI, 1.009-1.074). The rate of segmental aneuploidies was significantly higher in the older versus younger paternal age group (36.6% vs. 19.4%).

CONCLUSION(S)

No association was found between paternal age and aneuploidy rates in embryos derived from IVF cycles using young oocyte donors, after adjusting for donor, sperm, and IVF cycle characteristics. Advanced paternal age ≥ 50, compared with younger paternal ages, was associated with a lower fertilization rate and increased rate of segmental aberrations.

Sperm DNA fragmentation on the day of fertilization is not associated with embryologic or clinical outcomes after IVF/ICSI

PURPOSE

To evaluate if sperm DNA fragmentation (SDF) in the sample used for intracytoplasmic sperm injection (ICSI) impacts outcomes after euploid blastocyst transfer.

METHODS

Prospective cohort study of couples undergoing IVF with preimplantation genetic testing for aneuploidy from December 2014-June 2017. Sperm collected on the day of ICSI was analyzed for SDF using the sperm chromatin structure assay (SCSA®). Semen analysis parameters, embryologic outcomes, and clinical outcomes after euploid blastocyst transfer were compared between groups with DNA fragmentation index (DFI) ≤ 15% and DFI > 15% using Mann-Whitney U, t tests, and generalized linear mixed effects models.

RESULTS

Two hundred thirty-four patients were included. One hundred seventy-nine men had DFI ≤ 15% (low DFI group) and 55 men had DFI > 15% group (high DFI group). Total motile sperm and sperm concentration were significantly lower in the group with DFI > 15% vs. DFI ≤ 15%. There was no difference in fertilization (86.3 vs. 84.2%, adjusted OR (95% CI) 0.86 (0.63-1.18)), blastulation (49.5 vs. 48.8%, adjusted OR 1.02 (0.75-1.36)), or euploidy (55.7 vs. 52.1%, adjusted OR 0.96 (0.7-1.31)) between the low and high DFI groups, respectively. Clinical outcomes were similar between low and high DFI groups, including implantation rate (68.8 vs. 79.8%), ongoing pregnancy rate (65.9 vs. 72.6%), and miscarriage rate (4.2 vs. 8.8%), respectively.

CONCLUSION

Sperm DNA fragmentation on the day of ICSI is not associated with embryologic or clinical outcomes after euploid blastocyst transfer. Increasing levels of SDF are associated with low sperm concentration and total motile sperm count.

Sperm chromatin condensation defects, but neither DNA fragmentation nor aneuploidy, are an independent predictor of clinical pregnancy after intracytoplasmic sperm injection

PURPOSE

The impact of sperm DNA damage on intracytoplasmic sperm injection (ICSI) outcomes remains controversial. The purpose of the study was to evaluate the prognostic value of several types of sperm nuclear damage on ICSI clinical pregnancy.

METHODS

Our retrospective study included a total of 132 couples who consulted for male or mixed-factor infertility that benefited from ICSI cycles from January 2006 to December 2015. All infertile males presented at least one conventional semen parameter alteration. Sperm nuclear damage was assessed using the Motile Sperm Organelle Morphological Examination for sperm head relative vacuolar area (RVA), aniline blue staining for chromatin condensation, terminal deoxynucleotidyl transferase dUTP nick-end labeling for DNA fragmentation, and fluorescence in situ hybridization for aneuploidy.

RESULTS

Infertile males who achieved pregnancy after ICSI had fewer chromatin condensation defects than did males who did not achieve any pregnancy (15.8 ± 12.0% vs. 11.4 ± 7.9%, respectively, P = 0.0242), which remained significant in multivariate regression analysis (RR = 0.40 [0.18 to 0.86], P = 0.02). RVA, DNA fragmentation, and aneuploidy were not predictive factors of ICSI outcomes. The pregnancy rate was significantly decreased by number of progressive motile spermatozoa with normal morphology after migration (P = 0.04). In female partners, 17β estradiol of less than 2000 pg/mL on the day of ovulation induction significantly reduced the occurrence of clinical pregnancy (P = 0.04).

CONCLUSION

Sperm chromatin condensation defects were more frequently observed in couples with ICSI failure and should be considered a negative predictive factor for the occurrence of clinical pregnancy.

Paternal age: Negative impact on sperm genome decays and IVF outcomes after 40 years

This study assessed sperm quality declining on relation to paternal age and its impact on in vitro fertilization (IVF) outcomes in order to estimate the APA (Advanced Paternal Age) cutoff. For this, 83 couples undergoing IVF treatment for male factor infertility were enrolled. The women age was ≤39 years, whereas the men were divided in two groups: APA (n = 41; age ≥ 40 years) and young (Y) (n = 42; age < 40 years). Conventional semen parameters (volume, concentration, motility, vitality, and morphology) were analyzed in the collected sperm samples. Furthermore, sperm genome decays (SGD) was assessed by TUNEL assay (DNA fragmentation), aniline blue staining (chromatin decondensation), and fluorescent in situ hybridization (aneuploidy). No significant difference was found concerning the conventional semen parameters between APA and Y groups. Conversely, SGD analysis showed increased DNA fragmentation; chromatin decondensation and sperm aneuploidy rates in the APA group (respectively, 41%, 43%, and 14% vs. 25%, 23%, and 4% in Y group). IVF outcomes also were affected by paternal age as indicated by the rates of cancelled embryo transfers, clinical pregnancy and miscarriage in the two groups APA and Y (29%, 17%, and 60% vs. 10%, 32%, and 42%). Finally, statistical analysis of the results suggests that the age of 40 should be considered as the APA cutoff during ART attempts.

Influence of extended incubation time on Human sperm chromatin condensation, sperm DNA strand breaks and their effect on fertilisation rate

The purpose of this study was to determine influence of extended incubation time on sperm chromatin condensation and DNA strand breaks and their effect on fertilisation rate. Forty couples undergoing ICSI therapy were included. Semen was prepared by PureSperm gradient centrifugation and divided into two parts. The first part (G1) was used immediately for ICSI, whereas the second part (G2) was kept in the incubator at 37°C, 5% and 90% Humidity for 5 hr, and thereafter, the capacitated spermatozoa were used for ICSI. The TUNEL test and chromomycin CMA3 were used to evaluate the DNA strand breaks and chromatin condensation respectively. The percentage of condensed chromatin was 73.92 ± 12.70 in the group 1 and 81.13 ± 10.31% in group 2 (p = .001). However, the double-strand breaks were 11.15 ± 8.67% in G.1 and 16.30 ± 11.12% in G.2. (p = .001). Fertilisation rate in the (Group 1) was 62.45% and 69.17% in (Group 2). There was a positive correlation between condensed chromatin and fertilisation rate (r = 0.846, p = .001) and a negative correlation with DNA double-strand breaks (r = -0.802; p = .001). In conclusion, the prolonged sperm incubation (5 hr) leads to a higher chromatin condensation and to a significantly increased number of DNA strands double breaks with no influence on fertilisation rates.

Effect of Gonadotropin Types and Indications on Homologous Intrauterine Insemination Success: A Study from 1251 Cycles and a Review of the Literature

Objective

To evaluate the IUI success factors relative to controlled ovarian stimulation (COS) and infertility type, this retrospective cohort study included 1251 couples undergoing homologous IUI.

Results

We achieved 13% clinical pregnancies and 11% live births. COS and infertility type do not have significant effect on IUI clinical outcomes with unstable intervention of various couples' parameters, including the female age, the IUI attempt rank, and the sperm quality.

Conclusion

Further, the COS used seemed a weak predictor for IUI success; therefore, the indications need more discussion, especially in unexplained infertility cases involving various factors. Indeed, the fourth IUI attempt, the female age over 40 years, and the total motile sperm count <5 × 10⁶ were critical in decreasing the positive clinical outcomes of IUI. Those parameter cut-offs necessitate a larger analysis to give infertile couples more chances through IUI before carrying out other ART techniques.

Impact of alcohol and cigarette smoking consumption in male fertility potential: Looks at lipid peroxidation, enzymatic antioxidant activities and sperm DNA damage

Alcohol intake and cigarette smoking are the major lifestyle factors with negative impact on fertility. We were interested to evaluate the negative impact of these factors on oxidative stress (OS), enzymatic antioxidant activity (EAO) of spermatozoa and on its DNA damage. This study included 108 male infertile patients with normal range of sperm conventional parameters but with unexplained infertility in assisted reproductive technologies programme. Firstly, OS was analysed based on lipid peroxidation (MDA) and EAO which included catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR). Secondly, we evaluated DNA fragmentation by TUNEL assay and chromatin decondensation by aniline blue colouration. The whole lot was divided into four groups: control (nonalcoholic and nonsmoker patients), alcohol group, smoking group and alcohol-smoking group. The results showed, in three last groups compared to control an increased CAT, SOD and GR activities with high MDA level especially in smoking and alcohol-smoking group. The latter showed the highest values of DNA fragmentation and chromatin decondensation (31% and 39%) to exceed DNA damage normal range. Indeed, smoking and alcohol intake lead to increase EAO due to long-term unbalanced antioxidant/oxidation ratio with high OS which cause consequently sperm DNA damage calling in need by urgency to change the lifestyle behaviour.