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American Journal of  Medical 
Science and Innovation (AJMSI) 

A Systematic Review on Infertility in Men Due to Sperm DNA Damage: Causes
Investigations, & Management
Muna Rashed Al Khaldi1*,  Manal Al-khaldi2

Volume 2 Issue 2, Year 2023
ISSN: 2836-8509 (Online)

DOI: https://doi.org/10.54536/ajmsi.v2i2.1967
https://journals.e-palli.com/home/index.php/ajmsi

Article Information ABSTRACT

Received: August 12, 2023
Accepted: September 09, 2023
Published: September 18, 2023

The prevalence of  sperm DNA damage is common in infertile men, caused by several 
factors. This systematic review aims to conclude causative agents, advanced and effective 
diagnostic aids, and treatment plans. After a critical review of  1123 articles and research 
papers collected from Google Scholar, Pub-Med, the Database of  Abstracts of  Reviews of  
Effects, Embase, PsycINFO, Ovid Medline, and Cochrane Central Register of  Controlled 
Trials, 14 reviews have been included in this systemic review according to PRISMA guidelines. 
Included studies describe sufficiently regarding cause, investigations and management of  
infertility in men caused by sperm DNA damage. According to the results, 14 reviews have 
been eligible for this systemic review. The subject of  these reviews is associated with sperm 
DNA damage in men, causing infertility. These reviews summarised Oxidative stress as one 
of  the major causative factors. Different diagnostic tools have advantages, making them 
suitable for the scenario. It summarises that the factors affecting male infertility are general 
worldwide. This review could provide fundamental strategic plans dealing with specific risk 
factors and managing accordingly.

Keywords
Dna Damage, Infertility, 
Oxidative Stress, Sperm,  
Sexual Intercourse

1 Department of  Medicine and Surgery, Cairo University, Egypt
2 Department of  Medicine, King Hamad University Hospital, Al Sayh, Bahrain
* Corresponding author’s e-mail: munaalrashid32@outlook.com

INTRODUCTION
Infertility has been present in around 20 – 30 % of  males 
worldwide. It is observed that almost one-third time, the 
cause of  infertility in couples is men (Babakhanzadeh 
et al., 2020). Infertility relates to the failure to conceive 
a pregnancy after a suitable time of  sexual intercourse. 
Although, it could be due to the inability of  the pregnancy 
via natural means, or it could be a successful pregnancy 
that does not lead to a newborn baby (Brugo-Olmedo 
et al., 2001). The inability to cause infertility has many 
causative agents, including a person’s lifestyle. Increased 
use of  mobile phones, decreased physical activity, 
increased alcohol intake, and smoking. The destruction 
of  the human male genital system causes disruptions in 
spermatogenesis, which could lead to infertility (Muratori 
& De Geyter, 2019). Infertility in men could be due to the 
impacts of  the environment, nutritional deficiency, and 
genetics, and it may be idiopathic (Bisht et al., 2017).
The disruption of  the chromosomes could also affect the 
characteristics and functioning of  the sperm (Sharma, 
2017). Environmental factors are also responsible for 
deviating from the physiologic nature of  human systems. 
These factors are mostly related to the inclusion of  
xenobiotics in the diet. It includes chemical substances 
which could disturb the endocrine system and estrogen 
metabolism. Metals with high atomic mass, including 
Cadmium (Cd), lead (Pb), and mercury (Hg), damage 
the human reproductive system by destroying the 
hypothalamic-pituitary communication axis and 
disrupting spermatogenesis. This would produce semen 
with abnormal properties (Sharma, 2017).
Oxidative stress plays the most important role in the 
development of  genetic disorders. Its presence is caused 

due to excessive production of  Reactive Oxygen Species 
(ROS). The ROS could modify the DNA into single 
and double strands, break DNA fragmentation, alter 
nitrogen bases and deoxyribose properties, and change 
crosslinking. These modifications of  DNA could interpret 
the genetic stability and causes replication errors. DNA 
fragmentation is the last step of  the ROS action, resulting 
in single or double-stranded fragments (Bui et al., 2018).
Diabetes Mellitus, Obesity, Hyperthermia, and Genital 
tract infections could also be the causative agents of  
infertility. Varicocele is a condition in which the veins of  
the scrotum have enlarged and dilated due to defective 
valves. It causes impairment of  sperm production, 
decreased blood circulation, and reduced functions of  
Leydig cells. Varicocele positively affected ROS and 
sperm DNA fragmentation (Panner Selvam et al., 2021).
There is a need for an effective diagnostic strategy. 
Different and effective investigations, including assays, 
would be used to diagnose infertility in men caused by 
sperm DNA damage. However, infertility is a major health 
concern and exacerbates negative effects on a couple’s life 
and pregnancy. Explanation of  causative agents, diagnosis, 
and proper management are extremely important. This 
systematic review presents leading factors, investigating 
aids, and worldwide treatment planning.

LITERATURE REVIEW
Infertility is a complex condition that impacts 
approximately 15% of  couples, characterised by the 
inability to naturally conceive after engaging in regular 
unprotected sexual intercourse for 12 months or more. 
Notably, male factors are accountable for nearly 50% 
of  all infertility cases, making an equal contribution to 



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female factors (Omolaoye et al., 2022). Numerous factors 
and risk elements have been established as contributors 
to male infertility. Among these are smoking, alcohol 
consumption, substance abuse, obesity, historical or 
ongoing testicular infections, contact with environmental 
pollutants, prolonged exposure of  the testes to elevated 
temperatures, hormonal imbalances, past testicular 
injuries, and difficulties related to ejaculation or 
achieving an erection, among various others (Okonofua 
et al., 2022). In diagnosing male infertility, conventional 
assessment methods often rely on analysing standard 
semen parameters, as outlined by the World Health 
Organisation (WHO) guidelines. Nevertheless, many 
males experiencing infertility do not receive a definitive 
diagnosis, leaving their condition as idiopathic or 
unexplained (Mannucci et al., 2022). 
The assessment of  semen parameters following the 
WHO guidelines is currently considered the gold 
standard for diagnosing male infertility. Nevertheless, 
numerous studies have indicated that sperm quality can 
be adversely affected by oxidative stress-induced sperm 
oxidation, leading to a decline in sperm’s ability to fertilise 
(Mannucci et al., 2022). Given this compelling evidence, 
there is a growing need for novel tests to assess male 
fertility by monitoring oxidative stress levels. These new 
assays for detecting oxidative stress have the potential to 
revolutionise male infertility diagnosis and management 
by offering simpler, faster, and more cost-effective 
techniques (Agarwal, Parekh, et al., 2019). Oxidative stress 
can be assessed through biochemical tests, including 
plasma, serum, urine, and bodily fluids such as follicular, 
peritoneal, and seminal fluid. These assessments provide 
a precise overview of  the body’s redox status, enabling 
the potential implementation of  therapeutic antioxidant 
supplementation when necessary (Agarwal, Parekh, et al., 
2019). Various assays for evaluating oxidative stress are 
available, focusing on measuring ROS production, lipid 
peroxidation products, and total antioxidant capacity. 
When it comes to measuring ROS levels in semen, 
there are several methods to choose from, including 
chemiluminescence, the Nitro Blue Tetrazolium (NBT) 
test, cytochrome c reduction test, and electron spin 
resonance (Dutta et al., 2019b; Mannucci et al., 2022). 
The absence of  well-defined guidelines for treating 

male infertility associated with oxidative stress is partly 
due to an incomplete understanding of  its underlying 
causes (Agarwal et al., 2018). However, over recent years, 
numerous clinical trials have sought to explore the impact 
of  antioxidant supplementation, such as l-carnitine, 
selenium, Coenzyme Q10, ubiquinol, vitamin C, and E 
on oxidative stress levels in seminal fluid and various 
semen parameters (Alahmar et al., 2021). Many of  these 
trials have reported encouraging findings regarding the 
positive effects of  antioxidants on critical aspects like 
sperm concentration, motility, morphology, and DNA 
fragmentation. Specifically, the analysis included twenty 
clinical trials that focused on the effects of  anti-oxidant 
therapy on seminal oxidative stress. Notably, nineteen of  
these trials demonstrated improvements in sperm redox 
status and semen parameters, often correlating with 
improved pregnancy outcomes (Alahmar et al., 2021). 
The use of  antioxidant treatment to treat male infertility 
is critical to emphasise. Infertile men who received 
antioxidant treatment for three months did not experience 
any discernible improvements in DNA fragmentation 
or semen characteristics, according to one randomized 
clinical trial (Alahmar et al., 2021). Additionally, this study 
found no appreciable improvements in pregnancy or live 
birth rates. These observations highlight the ongoing 
uncertainty surrounding using antioxidants in addressing 
male infertility. Nonetheless, the combined evaluation of  
traditional semen analysis and oxidative stress assessment 
holds substantial promise for accurately assessing infertile 
patients (Gambera et al., 2019).

MATERIALS AND METHODS
The systemic review has been completed according to 
the guidelines regulated by Preferred Reporting Items for 
Systemic Research and Meta-Analysis (PRISMA) (Page et 
al., 2021).

Search Strategy
Search strategy based on the use of  MeSH terminologies 
which were related to the topic, mentioned in Table 1. 
The terms have been utilised appropriately using Boolean 
operators: AND, OR, and NOT. A typical summary of  
the study search has been described through the PICO 
model in Table 2.

Table 1: Search Strategy
Sr. no Search Strategy
1 Sperm DNA Damage [Abstract & Keywords] OR Male Infertility [Abstracts & Keywords] OR Infertility 

[Abstract & Keywords] OR Causes of  DNA Damage  [Abstract & Keywords] OR Reproductive System 
[Abstract & Keywords] OR Oxidative Stress [Abstract & Keywords] OR DNA Fragmentation [Abstract 
& Keywords]

2 Defective Sperm Production [tw] OR Immobile Sperm [tw] OR Unsuccessful Pregnancy [tw] OR Infertility 
of  Male [tw] OR Internal and External Factors [tw] OR Factor causing Sperm Immobility [tw] OR Factors 
causing Sperm DNA Damage [tw] OR Detection [tw] OR Treatment [tw] OR Management [tw] 

3 Treatment Options [Abstract & Keywords] OR Defective Spermatogenesis [Abstract & Keywords] OR 
Sperm DNA Fragmentation [Abstract & Keywords] OR Assisted Reproductive Technologies [Abstract 
& Keywords] OR Reactive Oxygen Species [Abstract & Keywords] OR Fertilisation Failure [Abstract & 
Keywords] OR Infertility [tw] OR DNA Integrity Tests [tw]



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Study Selection & Eligibility
The databases used to complete the search strategy and 
collect the required articles include Google Scholar, Pub-
Med, the Database of  Abstracts of  Reviews of  Effects, 
Embase, PsycINFO, Ovid Medline, and Cochrane 
Central Register of  Controlled Trials. Selective Keywords 
were used according to the required topics. Original 
Articles, Case reports, and Systematic Reviews published 
from January 2018 to March 2023 have been selected 
and analysed according to their principal objective 
and presented topic. The studies focused primarily on 
managing infertility in men and secondarily on causes of  
and diagnostic options for sperm DNA damage.

Inclusion Criteria
Reviews published between January 2018 to March 2023 
have been included. Reviews could be performed in any 
part of  the world. Men with infertility caused due to 
sperm DNA damage were the sample size. Sperm DNA 
damage is caused due to several internal and external 
causes, mainly increased oxidative stress and Apoptosis. 
DNA damage has been confirmed using different 
laboratory methods, including sperm DNA integrity tests 
and sperm DNA fragmentation testing. Included studies 
had delivered proven and justifiable data and results. They 
had published in the English language. Systemic reviews 
have been chosen related to the pathophysiology, aetiology, 
and management of  infertility in men due to sperm DNA 
damage. These reviews have a high impact factor.

Exclusion Criteria
Reviews conducted before January 2018 were excluded. 
Excluded studies had inaccurate and inappropriate 
data published in languages other than English. Studies 
had been excluded due to difficulty accessing their full 
text; also, Dissertations and Thesis had been rejected 
due to the inclusion of  only articles that used different 
epidemiological methods.

Data Extraction and Risk of  Bias
The two authors reviewed and decided to include all 
reviews independently based on the PICO model (Table 
2). Using Microsoft Excel and a standardised data 
extraction form, the researchers extracted and sorted 
the sample size, study type, duplicates, full-text articles, 
and empirical studies, making the systematic review 
approach practicable. Information of  variables includes 
the author, year of  publication, and number of  studies. 
The two reviewers assessed the methodological qualities 

by using the 7-item scale of  risk of  bias developed by 
the Cochrane Bias Methods Group. This review used the 
PRISMA guideline and flow diagram to lower the risk of  
bias. The sources of  bias assessed included outcomes, 
population, study selection process, incompleteness of  
data, and time frame and setting.

Quality of  Systematic Reviews
The expert team members assessed the quality of  the 
systematic reviews, including questions regarding the 
degree to which the systematic reviewers had evaluated 
the risk of  bias in individual studies. Systematic reviews 
with major limitations were excluded. The Authors 
have assessed the methodological quality of  studies in 
sperm DNA fragmentation based on the review authors’ 
assessments of  risk of  bias in the primary studies they 
had included.

Summary Measures and Synthesis of  Results
The authors analysed the data collected by the members 
of  the expert team. Due to the expected heterogeneity of  
studies regarding participants, interventions, outcomes 
and study designs, a quantitative summary measure of  the 
results was not planned. We did a qualitative and narrative 
summary of  the results of  the systematic reviews. The 
literature review results were presented and discussed in 
two workshops intending to validate results.

RESULTS AND DISCUSSIONS
A total of  1123 studies have been reached through 
search engines, including Google Scholar, Pub-Med, the 
Database of  Abstracts of  Reviews of  Effects, Embase, 
PsycINFO, Ovid Medline, and Cochrane Central 
Register of  Controlled Trials. These studies have been 
sorted according to their keywords and text words. After 
screening for duplicate and ineligible studies, 561 studies 
were excluded, according to PRISMA guidelines, as 
mentioned in Figure 1. Out of  562 studies, 341 have been 
rejected due to not meeting inclusion criteria. The reports 
of  179 studies could not be retrieved. 28 studies have been 
excluded due to some other reasons. After completing the 
literature search, 14 studies were retrieved, included in 
this systemic review and noted in Table 3.
The central idea of  included studies revolves around the 
causes, diagnostic aids, and management strategies of  
infertility in men. The studies included being from January 
2018 to March 2023. The included reviews specifically 
highlighted the causes and significance of  existing 
methods used for this purpose. They have discussed and 

Table 2: PICO Model
Population Male, Adult, Mature, Infertile.
Intervention Analysis of  the studies regarding causes of  sperm DNA damage, types of  investigation to detect 

DNA damage, and management plan to treat infertility caused due to sperm dysfunction.
Comparison Reviews had been included having views favouring the management of  infertility and against this approach.
Outcome This systemic review contained a novel idea of  new and distinctive management methods which 

would benefit patients facing Infertility.



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Figure 1: PRISMA flow diagram of  article selection criteria

Table 3: Studies included in the Systemic review
S r. 
no

Title Reference Sample 
size

Description Year

1 Role of  sperm DNA 
fragmentation in male factor 
infertility: A systematic review

29 150 This systemic review highlighted the 
importance of  DNA integrity assays in 
infertility diagnosis. It provides a new 
pathway for clinicians to detect infertility in 
men by applying SDF testing.

2018

2 A systematic review on sperm 
DNA fragmentation in male 
factor infertility: Laboratory 
assessment

38 87 studies 
& 8 book 
chapters

This systemic review discusses and 
compares different techniques used 
in diagnosing impotence. Its main 
emphasis was on the TUNEL method.

2018

3 The effects of  varicocelectomy 
on the DNA fragmentation 
index and other sperm 
parameters: a meta-analysis

47 289 
patients 
from 7 
prospective 
studies

This meta-analysis discusses the 
significance of  varicocelectomy in an 
infertile male. Results show a positive 
impact on sperm mobility, concentration, 
and morphology.

2020

4 Obesity and metabolic 
syndrome associated with 
systemic inflammation and 
the impact on the male 
reproductive system

11 N/A This review article deeply elaborates 
on the effects of  obesity and metabolic 
syndromes on the prevalence of  
infertility. These may negatively affect 
semen quality and spermatogenesis.

2019



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5 Sperm DNA Damage and 
Its Relevance in Fertility 
Treatment: A Review of  
Recent Literature and Current 
Practice Guidelines

12 N/A It discusses the treatment methods 
for male infertility, including surgical 
and non-surgical procedures. These 
techniques include the use of  testicular 
sperms, varicocelectomy, and use of  
microfluidic sperm sorting.

2023

6 Etiologies of  sperm DNA 
damage and its impact on male 
infertility

7 N/A This review elaborates on the 
mechanisms of  DNA damage and its 
impact in different scenarios of  male 
infertility associated with spontaneous 
and assisted reproduction. It also 
reviews the clinical applicability of  
sperm DNA fragmentation testing in 
the management of  male infertility

2021

7 What should be done for 
men with sperm DNA 
fragmentation?

34 N/A This review explains that sperm DNA 
damage testing methods do not have 
standardised cut-off  levels. Each method 
has advantages and disadvantages, 
making it difficult to proclaim one as a 
universally preferable method.

2018

8 Oxidative stress and sperm 
function: A systematic 
review on evaluation and 
management

25 N/A According to this review article, 
Oxidative stress is an important cause 
of  male factor infertility. Its assessment 
provides essential information to guide 
treatment strategies to improve the 
male's reproductive potential.

2019

9 The effects of  oral 
antioxidants on the semen 
of  men with idiopathic 
oligoasthenoteratozoospermia

54 N/A Most of  the studies in this review 
were randomised controlled studies 
that explored the effects of  oral 
antioxidants in men with idiopathic 
OAT. They reported improvements in 
at least one semen parameter (motility, 
concentration, normal morphology, 
and antioxidant capacity). Still, the most 
remarkable effect was that multiple 
antioxidants for 3–6 months increased 
sperm motility and concentration.

2018

10 Sperm DNA damage and its 
impact on male reproductive 
health: a critical review for 
clinicians, reproductive 
professionals and researchers

33 N/A This review discusses the origin and 
factors contributing to sperm DNA 
damage, the molecular changes, 
especially proteomic alterations caused 
due to SDF, risk factors associated with 
SDF, methods used to analyse SDF, 
clinical implications of  SDF, and CPG 
recommendations for SDF testing

2019

11 Oxidative stress and 
reproductive function: sperm 
telomerase, oxidative stress, 
and infertility

22 N/A This review article emphasises the proper 
diagnosis and measurement of  oxidative 
stress before any telomere evaluation in 
the ART setting. This review is focused 
on the telomere; the implications of  
the proposed mechanism extend far 
beyond that to any GQ sequence and 
offer novel, added insight into oxidative 
stress-induced epigenetic regulation/
dysfunction of  the paternal genome.

2022



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12 Effect of  varicocele repair on 
sperm DNA fragmentation: a 
review

45 N/A It explains the role of  varicocele repair 
in alleviating SDF and improving fertility 
and critically appraises the evidence-
based algorithm recently issued by the 
Society for Translational Medicine to 
guide urologists on using SDF testing in 
men with varicocele-seeking fertility.

2018

13 Single and Double Strand 
Sperm DNA Damage: 
Different Reproductive 
Effects on Male Fertility

41 N/A This review explains the etiology of  
sperm DNA damage highlighting the 
single and double-strand DNA damage. 
It also covers the management strategies 
to treat or reduce the effects of  sterility 
in men due to DNA fragmentation.

2019

14 Sperm DNA fragmentation: 
causes and identification

43 N/A This review describes the main causes of  
sperm DNA fragmentation and the tests 
commonly used to evaluate sperm DNA 
fragmentation.

2020

compared treatment options based on their requirements 
and effectiveness.
This systemic review consists of  a total of  20 studies 
which includes review articles, original studies, 
randomised control trials, and systemic considerations. 
These studies provided valid and accurate information 
regarding the pathophysiology, mechanism of  action, 
causes and aetiology, investigations and treatment plans. 
The main focus is on the advanced and new ways of  
management of  infertility in men. The germ cells in men 
are equally responsible for pregnancy. Damage to their 
genetic material affects their morphology and physiology 
and produces its outcome in future offspring. Most 
of  the studies elaborate on different causes of  sperm 
DNA damage, which triggers the process of  DNA 
fragmentation. These causes include abortive Apoptosis, 
increased oxidative stress, and endocrinal issues (Homa et 
al., 2019; Kuchakulla et al., 2021).

Risk Factors for Infertility
According to Leisegang et al. (2019), obesity and metabolic 
syndromes have affected the population worldwide with 
the complex underlying pathophysiological phenomenon. 
Metabolic syndromes result from an increased ratio 
between energy intake and energy consumption. Excessive 
energy deposits in the body affect body functions due 
to reduced physical activities. Environmental toxins, 
diet quality, inactive and sedentary lifestyles, hormonal 
changes, and pharmaceutical agents also cause metabolic 
imbalance and obesity (Leisegang et al., 2019). Avoidance 
of  Selective Serotonin Reuptake Inhibitors (SSRI), 
cigarette smoking, air pollution, and cancer treatments 
could be useful in decreasing the prevalence of  sterility. 
These are risk factors for sperm DNA fragmentation 
(Esteves et al., 2021; Marinaro & Schlegel, 2023; Schulte 
et al., 2010; Sharma et al., 2016; Ståhl et al., 2006; Tanrikut 
et al., 2010).
Sperm DNA fragmentation caused due to several extrinsic 
and intrinsic factors. Intrinsic factors include immature 

germ cells, abortive Apoptosis, and increased oxidative 
stress, while extrinsic factors include negative impacts of  
medicines, environmental factors, and lifestyles (Barazani 
et al., 2014; Muratori et al., 2019; Sakkas et al., 1999). 
Reactive Oxygen Species (ROS) are a major cause of  
sperm DNA fragmentation. These species produce in 
the mitochondrial DNA of  sperm and induce cascades 
and pathways leading to germ-cell Apoptosis (Agarwal 
et al., 2020; Moazamian et al., 2022). The process of  
spermatogenesis and sperms are more prone to damage 
from radiation than other body cells. Side effects of  
radiotherapy include male infertility and testicular cancer. 
However, non-ionising radiation produced by mobile 
phones, Wi-Fi, microwave, and laptops could also damage 
the genetic material of  sperm (Kesari et al., 2018; McGill 
& Agarwal, 2014).
Dysfunctional spermatozoa cause an increased ROS 
body production, which develops through two pathways. 
The most abundant species is superoxide (O2-), which 
undergoes chemical reactions to yield Hydrogen peroxide 
(H2O2). Any inflammatory or infectious response could 
ignite the production of  macrophages and lymphocytes, 
producing many ROS species (Agarwal et al., 2003; Dutta 
et al., 2019a). The dilation of  veins entering the testicles, 
known as varicocele, is one of  the major reasons for 
male sterility. It increased the internal temperature of  
the testes and decreased oxygen level causing hypoxia. A 
higher incidence of  ROS bodies is proportional to the 
presence of  varicocele, reducing semen and sperm quality 
(Agarwal et al., 2006; Dutta et al., 2019a).
Effects of  sperm DNA fragmentation on the human body, 
including pregnancy loss, Intrauterine Insemination (IUI), 
and In-Vitro Fertilization (IVF). Due to the increased ratio 
of  SDF, the chances of  conceiving became negligible. A 
systematic review including around 3000 couple sample 
size indicates a high value of  pregnancy loss of  about 
2.16 times when using semen specimens with high SDF 
(Robinson et al., 2012). There is a strong relationship 
between increased SDF and bad IUI outcomes. A raised 



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SDF index of   >27% has a negative impact on pregnancy 
assisted by the IUI procedure (Bungum et al., 2007; 
Cho & Agarwal, 2018). Controversial results explain 
the correlation between SDF and successful pregnancy 
after IVF and Intracytoplasmic Sperm Injection (ICSI). 
The reason behind this could be the difference in their 
methods. There is a chance of  sperm exposure to 
oxidative stress during laboratory steps of  culture in IVF, 
whereas in ICSI, the spermatozoon is directly injected 
into an oocyte. This may cause a decrease in SDF due to 
less exposure to oxidative stress (Cho & Agarwal, 2018; 
Dumoulin et al., 2010; Lewis, 2013).

Diagnostic Aids
There are many techniques for investigating DNA 
damage, divided into two kinds, including direct 
DNA integrity assessment and indirect DNA integrity 
assessment. One of  the well-known methods is 
the terminal deoxynucleotidyl transferase-mediated 
deoxyuridine triphosphate nick end labeling (TUNEL) 
method. This method directly measures the sperm DNA 
damage using deoxyuridine triphosphate (dUTP), which 
binds to single and double-stranded DNA. It could 
detect a small sample of  sperm and should be applied 
on fresh or frozen samples. TUNEL is a time-consuming 
process that requires a standardised criterion among the 
laboratories. It also cannot evaluate immature sperms 
compared to other tests (Agarwal, Panner Selvam, et al., 
2019; Evgeni et al., 2014; Gorczyca et al., 1993; Kim, 2018).
Sperm Chromatin Structure Assay (SCSA) was initiated 
in the 1970s and became popular after some remodeling. 
It investigates the sensitivity of  sperm DNA to 
denaturation and deformation. This test is simple to 
perform with a commercially available kit. It could be 
used on several spermatozoa for detection, and its results 
could also be compared with the results of  other tests 
(Evenson et al., 1980; Kim, 2018). It requires expensive 
equipment, trained personnel to perform tests, and 
many spermatozoa (Agarwal, Panner Selvam, et al., 2019; 
Selvam & Agarwal, 2018). The comet assay or SCGE test 
is the qualitative testing of  DNA damage by detecting 
deformation in single and double DNA strands using 
electrophoresis (Kim, 2018; McKelvey-Martin et al., 
1997). It is a simple and affordable process whose results 
are based on the tail length of  sperm. The tail end of  the 
sperm carries fragments of  DNA which indicates DNA 
damage. Due to this reason, this test is not recommended 
by investigators (Agarwal, Panner Selvam, et al., 2019; 
Cho & Agarwal, 2018; Singh et al., 1989).
Sperm Chromatin Dispersion (SCD) or Halo test is a 
highly standardised process based on extracting proteins 
after acid denaturation producing halo characteristics. It 
detects single and double-stranded breaks in sperm DNA 
(Fernández et al., 2005; Ribas-Maynou & Benet, 2019). It 
is used extensively due to its low cost and quick results 
with quality. Sometimes it is difficult to differentiate 
the proximal borders of  the halo having low chromatin 
density from the background (Evgeni et al., 2014; Kim, 

2018). Chromomycin A3 (CMA3) staining detects the 
deficiency of  chromatin in sperm DNA by competing 
with protamine for the same binding site. Protamine 
deficiency indicates male infertility. This test strongly 
correlates with other SDF assays (Agarwal & Allamaneni, 
2005; Cho & Agarwal, 2018; dos Santos Hamilton & 
Assumpção, 2020; Selvam & Agarwal, 2018).

Management 
There are several ways of  managing infertility in men 
based on the cause. There are intrinsic as well as extrinsic 
factors causing sterility in men. Varicocele is a significant 
reason for male infertility, causing 15% of  the male 
population of  mature age. Dubin’s grading system is 
used to diagnose it and indicates its severity. There is a 
rise in ROS and apoptosis markers in the cytoplasm in 
patients diagnosed with varicocele (Miyaoka & Esteves, 
2011; Roque & Esteves, 2018). It causes testicular 
hyperthermia, affects endocrine functions, elevates 
hypoxia, causes defective spermatogenesis, and damages 
nuclear and mitochondrial DNA. Its treatment includes 
surgical intervention, that is, varicocelectomy, assisting in 
lowering the factors and reducing infertility. According 
to studies, after performing varicocelectomy using any 
technique retroperitoneal, inguinal, or subinguinal, there 
is a significant difference in the values of  preoperative 
and postoperative SDF levels in semen (Birowo et al., 
2020; Schauer et al., 2012). 
Another study shows a mark reduction in the value of  SDF 
after Varicocelectomy along with the mast cell stabilisers. 
It positively affects sperm mobility, concentration and 
increased sperm count. The degranulation of  mast 
cells is correlated with increased ROS production; a 
combination of  varicocelectomy and induction mast 
cell stabiliser has a more pronounced effect (Zaazaa et 
al., 2018). Varicocelectomy has increased venous blood 
drainage, decreasing ROS production and enhancing 
spermatogenesis and semen quality. The researchers 
do not recommend varicocelectomy in patients with 
normal semen quality and asymptomatic varicocele. 
Varicocelectomy indicates defective sperm motility and 
morphology (Birowo et al., 2020; EAU annual congress, 
2020; Zavattaro et al., 2018).
Oral antioxidant therapy has a depressing effect on 
the production of  ROS. Both intrinsic and extrinsic 
antioxidant can play their part in eliminating the ROS 
and shifting the curve toward the normal range. They 
could assist in destroying ROS bodies in semen and 
restore the redox balance (Agarwal, Panner Selvam, et 
al., 2019; Showell et al., 2014; Smith et al., 2006). Several 
antioxidants include vitamin A, vitamin C, and vitamin 
E. Several successful studies suggest antioxidants as one 
of  the best therapies for infertility with promising results 
(Adewoyin et al., 2017; Alahmar, 2018; Cho & Agarwal, 
2018; Tremellen, 2008). Lifestyles have also exerted a 
significant impact on infertility. Obesity and metabolic 
disorders cause incompetency and are severe systemic 
disorders, mostly caused due to sedentary lifestyle. A 



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healthy lifestyle and a balanced and hygienic diet are 
strongly associated with reduced male infertility (Omer 
& Atassi, 2017). A diet rich in carbohydrates, antioxidants 
containing vegetables, fibre, biogenic seeds, and seafood 
reduces inflammatory markers. These nutrients are 
related to an improved immune and neurological system, 
reduced fat accumulation and increased DNA integrity 
(Leisegang et al., 2019).

LIMITATIONS
Even though our search was broad and included many 
medical libraries, conference abstracts, and other 
unpublished pieces of  literature may get overlooked, 
causing limiting our conclusions. However, there is no 
literature on the routine investigations of  defective DNA 
in infertile men. Also, the mechanism of  antioxidants 
against the ROS bodies at the molecular level is not 
present, explaining its effects on semen quality, duration 
of  treatment and the choice of  therapeutics. In the future, 
this evidence could be taken into consideration.

Strengths
The review uses a comprehensive search strategy across 
multiple databases to gather relevant studies on male 
infertility caused by sperm DNA damage. It includes 
various study types, including review articles, original 
studies, randomised controlled trials, and systematic 
reviews. Moreover, the review’s clear presentation makes 
it easy to follow. The findings can inform clinical practice 
and guide healthcare professionals in improving patient 
care. Furthermore, the review also discussed emerging 
management methods, highlighting its forward-looking 
approach and potential future developments in the field. 

CONCLUSION
This systemic review summarised the most common 
causes of  infertility in men, damaging sperm DNA. 
This would include a sedentary lifestyle and intrinsic and 
extrinsic risk factors, which increase the level of  ROS in 
the testicular spermatozoa. The risk of  DNA damage is 
more evident during ejaculation. Oxidative stress could 
be controlled by prescribing antioxidants and planning a 
healthy and hygienic diet. Surgical intervention includes 
varicocelectomy, which also reduces the level of  ROS 
in the mitochondrial and nuclear DNA of  the sperms. 
Genital tract infections also cause infertility which should 
be diagnosed earlier and treated with broad-spectrum 
antibiotics. This review will provide substantial knowledge 
regarding the major causes of  infertility and how to 
improve it. Implications of  new management methods 
have been discussed, which could benefit the patients.

Novelty of  Research
This review provides a comprehensive and up-to-date 
information regarding male infertility due to sperm DNA 
damage. It focuses on recent research, a comprehensive 
approach, and emerging management methods. The 
review considers factors such as lifestyle, environmental 

exposures, and genetic influences. It also discusses 
established and emerging management strategies for 
male infertility. The research offers practical insights for 
healthcare professionals and patients, guiding decision 
making and patient care. The inclusion of  various study 
types adds depth and diversity to the analysis. Overall, 
this review offers a unique perspective on male infertility. 

Research Gap
This review on male infertility caused by sperm DNA 
damage identified several research gaps. These include 
the lack of  long-term follow-up studies, the impact of  
lifestyle interventions, standardisation of  diagnostic 
tests, environmental factors, psychological impact, cost-
effectiveness analysis, and exploring novel treatment 
approaches. The review also highlighted the need for 
more research on male infertility’s psychological and 
emotional implications, cost-effectiveness analysis, and 
more diverse study populations. Additionally, the review 
suggested the development of  biomarkers for predicting 
treatment success and a stronger emphasis on patient-
centered outcomes. These gaps could contribute to a 
more comprehensive understanding of  male infertility 
and the development of  more effective diagnostic 
methods and treatments.

Contribution to Knowledge
The systematic review on male infertility caused by sperm 
DNA damage provides a comprehensive overview of  the 
current state of  knowledge. It identifies causal factors, 
diagnostic methods, treatment strategies, and impacts 
on reproductive outcomes. The insights have practical 
implications for healthcare providers, researchers, and 
policymakers, enabling them to develop evidence-based 
treatment plans. The review also contributes to patient 
education by raising awareness of  factors contributing 
to male infertility and available diagnostic and treatment 
options.

Abbreviations
ROS: Reactive Oxygen Species; DNA: Deoxyribose 
Nucleic Acid; SDF: Sperm DNA Fragmentation; ICSI: 
Intra Cytoplasmic Sperm Injection; IVF: In Vitro 
Fertilization; CMA3: Chromomycin A3; SCD: Sperm 
Chromatin Dispersion; SCSA: Sperm Chromatin 
Structure Assay; TUNEL: Terminal Deoxynucleotidyl 
Transferase dUTP Nick End Labeling; DFI: DNA 
Fragmentation Index; IUI: Intra Uterine Insemination; 
PRISMA: Preferred Reporting Items for Systematic 
Reviews and Meta-Analyses; OS: Oxidative Stress; ART: 
Assisted Reproductive Technology.

Statement and Declarations
Data Availability Statement
The data utilised in writing this systemic review is 
obtained from previously presented original articles and 
reports. No new data or evidence has been created during 
this period.



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Authors Contribution
Conceptualisation, Data curation, supervision, validation, 
Writing-review and editing has been done by Author 
(MR). Methodology, software analysis, and writing of  the 
original draft have been done by Author (MK).

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