Role of intra-individual variation in the detection of thresholds for DFI and for misclassification rates: A retrospective analysis of 14,775 SCSA® tests.
By: Preben Christensen1, Robert Fischer2, Wolfgang Schulze2, Vera Baukloh2, Kimberly Kienast2, Graham Coull3 and Erik Parner4
Published in Andrology, November 2024. The publication can be viewed online and downloaded via DOI:10.1111/andr.13801 and PMID: 39545580.
An analysis of 14,775 tests of DNA fragmentation was conducted by SPZ Lab1, the Fertility Center Hamburg2, Sims IVF (Dublin)3 and Aarhus University4. The tests, which were performed between 2008 and 2022, reveal that DFI (DNA fragmentation index) increased during the period (statistically reliable).
The results show that 52.5% of the examined men had a DFI over 15 while 23.5% of the men had a DFI above 25. The chances of a successful pregnancy with IVF treatment are reduced when the DFI is over 15 (statistically reliable). For ICSI treatment (microinsemination), a corresponding reduction in the likelihood of achieving pregnancy occurs when the DFI is over 25.
Increasing DFI is linked with an increase in the risk that a couple will experience several disappointing fertility treatments.
Assessment of Sperm DNA Integrity and Implications for the Outcome of ICSI Treatments.
By: Preben Christensen and Anders M. Birck
Published in Springer: Intracytoplasmic Sperm Injection 2018, pp. 63-84.
A precise and correct assessment of DNA integrity in sperm cells is an essential method for achieving an effective fertility treatment, which involves a focus on the challenges faced by both the man and the woman.
This review examines the application of Sperm Chromatin Structure Assay (SCSA) and flow cytometry, which, in combination with thorough quality control, ensures very high-quality results.
Extensive DNA damage in the sperm cells plays a crucial role in natural fertility and the likelihood of pregnancy during insemination treatment (IUI). The influence is less, but still significant, for in vitro fertilisation (IVF) and micro-insemination (ICSI).
Regardless of whether the best embryos are selected for transfer, an increasing number of studies indicate that damage to DNA may result in miscarriage and may also have a negative effect on the health of the foetus.
Several studies have shown that, in the long term, men with reduced fertility also have an increased risk of a wide range of serious diseases including cancer and cardiovascular disease. Therefore, if the man has reduced fertility due to damage to the DNA, it is important to conduct a thorough investigation.
Sperm DNA damage and clinical recommendations.
By: Preben Christensen and Peter Humaidan
Published in Transl Androl Urol. 2017;6 (Suppl 4):S607–9. doi: 10.21037/tau.2017.03.34
The discussion about the clinical use of sperm DNA tests most frequently centres on the term ‘DNA fragmentation’, which is based on the ‘outdated’ hypothesis that the DNA of the sperm is stable and does not change.
However, the new ‘two-step’ hypothesis is based on the view that the DNA in the sperm cells of men with reduced fertility is more fragile and is, therefore, easily damaged during the sperm’s journey to the egg and fertilisation. Damage is a dynamic and progressive process, which in the worst-case results in double-strand DNA breaks, which is why the DNA breaks into fragments (i.e., fragmentation).
The new hypothesis explains why the various fertility treatments are affected to different extents.
Regarding the man with reduced fertility, it is important to clarify the possible reasons for the increase in the fragility of the DNA.
Regardless of the type of fertility treatment, correcting these factors will have a positive effect on the result of the treatment and will also contribute to the improved health of the child to be born.