Sperm DNA Fragmentation after Cryopreservation and Sperm Selection Has No Implications for Clinical Pregnancies and Live Births after Intrauterine Insemination with Donor Sperm

Intrauterine insemination with donor sperm (IUI-D) requires multiple in vitro manipulations such as sperm selection and cryopreservation during which spermatozoa may be exposed to oxidative stress (OS) and other insults that may produce potential damage including sperm DNA fragmentation (SDF). High levels of SDF, referring to damage or breaks in the genetic material of sperm cells, are linked to an increased risk of reproductive failure. This retrospective, observational study set out to evaluate whether SDF assessment could predict clinical outcome in an IUI-D program, where sperm donors are selected on strict conventional semen parameters. A total of 18 donors and 106 recipients were matched for IUI-D. Out of 429 cycles, 100 (23.3%) resulted in clinical pregnancy. We counted 78 live births (18.2% of cycles), while 20 pregnancies ended in miscarriage (4.7% of cycles), 1 in extra-uterine pregnancy and 1 in stillbirth. Female age significantly influenced clinical pregnancy and miscarriage rates. SDF increased after cryopreservation (26.3 ± 14.5%; p < 0.001) and more so after post-thaw density gradient (34.9 ± 22.1%; p = 0.04) without affecting clinical pregnancy (OR [95% CI] 1.01 [0.99; 1.02]; p = 0.27), live birth (1.00 [0.99; 1.02]; p = 0.72) and miscarriage rates (1.02 [1.00; 1.05]; p = 0.08). The implications of our findings extend to a better selection of sperm donors and a better sperm preparation technique tailored to the donor semen's properties in order to maximize the chances of a favorable treatment outcome.

Sperm DNA fragmentation index influences assisted reproductive technology outcome: A systematic review and meta-analysis combined with a retrospective cohort study

Studies have explored the influence of DNA damage in assisted reproductive technology (ART), but the outcome remains controversial. To determine whether sperm DNA fragmentation index (DFI) has any effect on ART outcomes, we collected detailed data regarding 1,333 IVF cycles performed at our centre, and the data of our retrospective cohort study were extracted for this meta-analysis. We searched PubMed, Web of Science, EMBASE and Google Scholar and performed a systemic review and meta-analysis. Primary meta-analysis of 10 studies comprising 1,785 couples showed that live birth rate was no significantly different between low-DFI group and high-DFI group (p > 0.05). Secondary meta-analysis of 25 studies comprising 3,992 couples showed a higher miscarriage rate in high-DFI group than in low-DFI group (RR=1.57 [1.18, 2.09], p < 0.01). Meta-analysis of eight studies comprising 17,879 embryos revealed a lower good-quality embryo rate (RR=0.65 [0.62, 0.68], p < 0.01). Meta-analysis of 23 studies comprising 6,771 cycles showed that the high-DFI group had a lower clinical pregnancy rate than low-DFI group (RR=0.85 [0.75, 0.96], p < 0.01). Heterogeneity of included studies weakened our conclusions. Our study showed that DFI has adverse effects on ART outcome. More well-designed studies exploring the association between DFI and ART outcome are desired.

Variants in DPF3 and DSCAML1 are associated with sperm morphology

PURPOSE

Abnormalities in semen parameters are often associated with reduced fertility in males, and may, in part, be attributed to genetic variation. Aim of this study is to determine if genetic variants that were previously shown to be predictors of family size and birth rate in healthy men are also associated with sperm morphology in men recruited from an infertility laboratory.

METHODS

Genetic associations with sperm morphology phenotypes in 126 ethnically diverse men from Chicago at 41 independent loci, previously shown to be predictors of family size and birth rate in healthy men, were tested.

RESULTS

Two intronic SNPs, rs680730 (in DSCAML1) and rs10129954 (in DPF3), were associated with the percent of normal sperm morphology in Chicago men (P = 0.017 and 0.023, respectively). Furthermore, both loci were associated with increased occurrence of sperm head defects.

CONCLUSIONS

SNPs in two genes, both of which have roles in nervous system development, were associated with poor sperm morphology. These results may be helpful in identification of other novel genes and biological pathways whose proper functioning is crucial for sperm production and male reproductive processes.

The clinical utility of sperm DNA integrity testing: a guideline

Sperm DNA damage is more common in infertile men and may contribute to poor reproductive performance. However, current methods for assessing sperm DNA integrity do not reliably predict treatment outcomes and cannot be recommended routinely for clinical use.

Routine cryopreservation of spermatozoa is safe--evidence from the DNA methylation pattern of nine spermatozoa genes

PURPOSE

Assess short- and mid-term impact of cryopreservation on DNA methylation status of different genes in spermatozoa.

METHODS

Semen samples from 10 healthy normozoospermic men were collected at the Department of Clinical Andrology of the Centre of Reproductive Medicine and Andrology (Muenster, Germany). Each was divided into four equal aliquots: 1) untreated, 2) diluted in cryoprotectant, 3) short term (2 days) cryopreserved and 4) mid term (4 weeks) cryopreserved. Samples were "swim-up" purified prior to analysis. DNA fragmentation was measured using comet assay and Flow cytometric evaluation with Acridine Orange (FCEAO). The degree of methylation of nine genes was determined by bisulfite pyrosequencing of genomic DNA.

RESULT(S)

Analysis of three maternally imprinted genes (LIT1, SNRPN, MEST), two paternally imprinted genes (MEG3, H19), two repetitive elements (ALU, LINE1), one spermatogenesis-specific gene (VASA) and one gene associated with male infertility (MTHFR) in semen samples demonstrated no alteration in methylation pattern regardless of duration of cryopreservation.

CONCLUSION(S)

The lack of any changes in the sub-fraction of the genome examined in our study, implies that sperm DNA methylation is unaffected by cryopreservation and suggests that this daily clinical routine is safe in terms of DNA methylation.

Effect of pre-freezing conditions on the progressive motility recovery rate of human frozen spermatozoa

We evaluated the effects of sperm concentration, progressive motility, sperm morphology, duration of abstinence and collection season on the progressive motility recovery rate of human frozen spermatozoa to identify characteristics that predict the progressive motility recovery rate of human frozen spermatozoa and improve the protocol for sperm collecting in sperm banks. A total of 14 190 semen samples donated at Zhejiang human sperm bank of China between September 2006 and June 2011 were collected from 1624 donors. Semen was evaluated according to WHO standard procedures for sperm concentration. Progressive motility, sperm morphology, ejaculate collection season and abstinence time were recorded. After freezing and thawing, the progressive motility was assessed. Results showed that sperm concentration, progressive motility and normal morphology were significantly associated with the progressive motility recovery rate of human frozen spermatozoa. In addition, the abstinence time and collection season also significantly affected progressive motility recovery rate. Our results indicated that sperm concentration, progressive motility and normal morphology could be valuable in predicting the progressive motility recovery rate of human frozen spermatozoa. As such, progressive motility recovery may be improved by donating semen when abstinent for 3-5 days and during seasons other than summer.