This document summarizes research on sperm DNA fragmentation in assisted reproductive technology. It finds that 20-60% of men with teratozoospermia and 20-40% of men with normal sperm parameters based on WHO standards have DNA fragmentation over 20-30%, which can cause infertility. Diagnostic tests like TUNEL and COMET assays are used to measure DNA fragmentation. Factors that can cause DNA fragmentation include oxidative stress, lifestyle factors like smoking, genetic factors, infections, varicocele, and advanced male age over 35. High levels of sperm DNA fragmentation are associated with lower fertilization rates, embryo quality, pregnancy rates, and higher miscarriage rates with IVF/ICSI. Selection of sperm with less DNA

1. Sperm DNA fragmentation in Assisted
Reproductive Technology
• Abimibola Nanna
• Clinical Embryologist
• MSc Clinical Embryology,
• University of Leeds

2. Introduction
• Sperm DNA integrity: Chromatin Structure
with haploid DNA and heterogeneous protein
• Sperm DNA fragmentation: Occurrence of the
alteration of chromatin configuration
• Sperm DNA fragmentation occurs in
– Oligoasthenoteratozoospermia
– Infertile males with normazoospermic parameters
– Couples with failed IVF process

3. % of DNA Fragmentation in different
groups-TUNEL positive

4. Contd
• 20%-60% of teratozospermia sample that have
normal sperm examined by strict criteria have
DNA fragmentation.
• 20%-40% of men with normal semen
parameters above WHO values, are in infertile
due to DFI of >20-30%
• 17.6% or lower DNA fragmentation in normal
spermatozoa result to 3.5 times higher
pregnancy rate.

5. Mechanism of Sperm DNA
Fragmentation
• Abortive apoptosis during meiosis 1
• Defective chromatin condensation during
spermiogenesis
• Post-testicular oxidative stress
• Endogenous caspase and endonuclease
activity

6. Diagnosis of Sperm DNA
Fragmentation
• Terminal deoxynucleotidyl transferase-
mediated dUTP nick and labelling-TUNEL.
• Single gel electophoresis-COMET
• Sperm Chromatin Dispersion-SCD
• Fluorescence in situ hybridization

7. Types of Sperm DNA Fragmentation
• Single or double DNA strands breaks
• Loss of a base to create a base site
• Oxidation or alkylation of base
• Membrane lipid peroxidation

8. Major causative factors of sperm DNA
fragmentation
• Leukocytospermia
• Cancer:
• Testicular cancer
• Leukaemia
• Lymphoma
• Cisplatin treatment
• Advanced Male Age .35
• ROS

9. Contd
• Lifestyle factors:
• Smoking
• Alcohol
• Environmental factors:
• Pesticides
• Chemical substances
• High temperature
• Radiation

10. Contd
• Genetic factors:
• Genetic variations in:
• DNA repair pathways
• Detoxification pathways
• Antioxidant genes
• Chromosome structural abnormalities:
• Reciprocal translocations
• Robertsonian translocations
• Pericentric inversions
• Chromosomal aberrations, Yq microdeletions

11. Contd
• Pathological factors:
• Prolonged duration of fever
• Varicocele
• Male genital tract infection
• Testicular torsion
• Cryptorchidism
• Hypospermatogenesis

12. Sperm DNA Fragmentation and Sperm
Morphology
• Spermatozoa morphology examined by strict
criteria may have sperm DNA fragmentation.
• Teratozoospermia index is a strong determinant
of DNA fragmentation index
• Increased sperm DNA fragmentation is associated
with globozoospermia.
• Tapered sperm head is associated with increased
sperm DNA fragmentation.
• Small sperm head is associated with increased
sperm DNA fragmentation

13. Effects of Sperm DNA fragmentation
on ART
• Fertilization failure
• Impaired embryonic development-
fragmentation and cell death
• Increased incidence of miscarriage-four fold
increased in IVF/ICSI
• Morbidity cases in offspring, including
childhood cancer
• Genetic transfer of DNA damage to new
generation

14. Contd
• Reduced implantation or pregnancy rate
• Abnormal behaviour-Schizophrenia
• Congenital malfunction
• Aberrant growth
• Premature aging

15. Pregnancy rate with low sperm DNA
fragmentation
• 6.5 to 10 fold in natural process
• 7 to 8.7 fold in IUI
• 2 fold in IVF
• 1.5 fold in ICSI

16. Selection of DNA-intact sperm in ART
• Antioxidant supplementation or life style
adjustment.
• 2-3 days abstinence
• Direct swim up
• Density gradient
• Hyaluronic acid binding method
• Host before ICSI
• Selection of spermatozoa under high
magnification-13,000x
• Good oocyte quality

17. Contd

18. Conclusion
• Male fertility is difficult to predict on one
semen variable
• Sperm DNA integrity is important in male
fertility potentials.
• This can be determine by both seminological
parameters and spermatozoal genomic
integrity
• This further improve the efficiency of ART
process.

19. Reference
• Wdowiak A, Raczkiewice D, Staslak N, Bojar I.(2014).
Levels of FSH, LH and Testosterone and Sperm DNA
Fragmentation. Neuroendocrinology Letters Volume
35, No1
• Jayaraman V, et al.Sperm processing by swim-up and
density gradient is effective in elimination of sperm
with DNA damage.J. Assist Reprod. Genet.
2012;29:557-563
• Avendano C, et al. DNA Fragmentation in
Morphologically Normal Spermatozoa: How Much
Should WE Be Concerned in the ICSI Era.Journal of
Andrology, Vol32,No4,July/August 2011

20. Contd
• Evgeni Evangelini , Konstantinus Charalabopoulos,
Byron Asimakopoulos. Human Sperm DNA
Fragmentation and its Correlation with Conventional
Semen Parameters.J. Reprod Infertil. 2014;15(1):2-14
• Meseguer M ,et al. Effect of Sperm DNA Fragmentation
on Pregnancy Outcome depends on Oocyte quality.
Fertility and Sterility Vol 85,No 1, January 2011
• Avendano C, et al. Fragmentation of DNA in
Morphologically normal human spermatozoa. Fertility
and Sterility. Vol 91, N0 4, April 2009

21. THANK YOU