III Methodology
Basic principles
The method used to prepare this guideline was determined by the class to which this
guideline was assigned. The AWMF Guidance Manual (version 1.0) has set out the respective
rules and requirements for different classes of guidelines. Guidelines are differentiated
into lowest (S1), intermediate (S2) and highest (S3) class. The lowest class is defined
as a set of recommendations for action compiled by a non-representative group of experts.
In 2004, the S2 class was divided into two subclasses: a systematic evidence-based
subclass (S2e) and a structural consensus-based subclass (S2k). The highest S3 class
combines both approaches.
This guideline was classified as: S2k
Grading of recommendations
Grading of evidence based on the systematic search, selection, evaluation and synthesis
of the evidence base which is then used to grade the recommendations is not envisaged
for S2k-level guidelines. The various individual statements and recommendations are
differentiated only by syntax, not by symbols ([Table 3 ]).
Table 3 Grading of recommendations.
Strength of recommendation
Syntax
strong recommendation, highly binding
must/must not
regular recommendation, moderately binding
should/should not
open recommendation, not binding
may/may not
Statements
Expositions or explanations of specific facts, circumstances or problems which are
not direct recommendations for action included in this guideline are referred to as
“statements”. It is not possible to provide any information about the grading of evidence for these statements.
Achieving consensus and strength of consensus
At structured NIH-type consensus-based conferences (S2k/S3 level), authorized participants
attending the session voted on draft statements and recommendations. The process was
as follows. A recommendation was presented, its contents were discussed, proposed
changes were put forward, and finally, all proposed changes were voted on. If a consensus
was not achieved (> 75% of votes), another round of discussions was held, followed
by a repeat vote. Finally, the extent of consensus was determined based on the number
of participants ([Table 4 ]).
Table 4 Classification showing extent of agreement underpinning consensus-based decisions.
Symbol
Strength of consensus
Extent of agreement in percent
+++
Strong consensus
> 95% of participants agree
++
Consensus
> 75 – 95% of participants agree
+
Majority agreement
> 50 – 75% of participants agree
–
No consensus
< 50% of participants agree
Expert consensus
As the name already implies, this refers to consensus decisions taken with regard
to recommendations/statements where no prior systematic search of the literature (S2k)
was carried out or for which evidence is lacking (S2e/S3). The term “expert consensus”
(EC) used here is synonymous with terms used in other guidelines such as “good clinical
practice” (GCP) or “clinical consensus point” (CCP). The strength of the recommendation
is graded as previously described in the chapter “Grading of recommendations”, i.e.,
purely semantically (“must”/“must not” or “should”/“should not” or “may”/“may not”),
without the use of symbols.
IV Guideline
1.1 Special aspects for patients with a prior history of oncologic disease in childhood,
adolescence or adulthood
As women with a history of oncologic disease face many unanswered questions with respect
to their future fertility which may significantly affect their quality of life [6 ], professional and possibly interdisciplinary counselling is necessary. Professionals
working in associated medical fields (e.g. oncologists, radiotherapists, geneticists,
etc.) should be consulted where necessary, ideally before the start of pregnancy.
Consensus-based recommendation 3.9.E51
Expert consensus
Strength of consensus +++
Patients with a history of oncologic disease who want to have children must be given
counselling by an interdisciplinary team.
1.1.1 Importance of pregnancy for underlying malignant disease
The patientʼs general condition, life expectancy, potential necessity to adapt an
existing maintenance regimen and the possible impact of ovarian stimulation or possible
pregnancy on the prognosis of the primary disease must all be considered along with
the opinions of professionals working in associated medical fields about specific
types of oncologic disease.
Consensus-based recommendation 3.9.E52
Expert consensus
Strength of consensus +++
Patients wanting to have children with distant metastatic oncologic disease must only
start reproductive medical treatment after ART has been approved by an interdisciplinary
team on a case-by-case basis.
It is also important to consider the risk of ovarian metastasis when cryopreserved
ovarian tissue resected prior to oncological treatment is transplanted back into the
patient after the end of treatment. The risk of metastasis varies considerably according
to the underlying tumor type ([Table 5 ]), meaning that for certain tumor entities such as leukemia. transplantation can
currently not be considered a safe option [23 ]. For details, please refer to the German-language AWMF guideline “Fertility Preservation
and Oncologic Disease,” register number 015-082 [22 ].
Consensus-based recommendation 3.9.E53
Expert consensus
Strength of consensus +++
When planning the transplantation of cryopreserved ovarian tissue into patients with
a history of oncologic disease, part of the tissue must be examined histologically
to exclude ovarian metastasis. Patients must also be informed in detail about the
risk of possible metastasis prior to transplantation, the associated risk of inducing
recurrence as well as the limited available data about these issues.
Consensus-based recommendation 3.9.E54
Expert consensus
Strength of consensus +++
Autologous ovarian transplantation should only be carried out if the patient wants
to have children. The patientʼs partner must also first undergo an andrological examination
prior to ovarian transplantation. Fallopian tube patency must be checked as part of
the preparation for transplantation. Where possible, ovarian transplantation must
be done on the side with a patent fallopian tube.
Table 5 Risk of ovarian metastasis depending on the primary tumor entity (modified [22 ]).
High risk
Moderate risk
Low risk
leukemia
neuroblastoma
Burkittʼs lymphoma
ovarian tumors
stage I – III breast cancer
invasive ductal subtypes
squamous cell carcinoma of the cervix
Hodgkinʼs lymphoma
osteosarcoma
extragenital rhabdomyosarcoma
Wilms tumor
After transplantation of cryopreserved ovarian tissue, signs of hormone activity usually
appear within 2 – 4 months after surgery. The following approach should be followed
to avoid unnecessary stress for the patient: if her period starts in the first 4 months
after transplantation, the patient must make an appointment with her treating physician.
Hormone levels (E2, LH, FSH, poss. progesterone, poss. AMH) should then be determined.
If the patient has still not had a period at 4 months after transplantation, then
she should present to a fertility center for further examination (see above). If hormone
activity is detected, then intervention may be postponed for a further two months
to see whether the patient starts her period in these two months. If no hormonal activity
is detected after 8 months, transplantation of further ovarian tissue (if available)
should be considered [4 ].
1.1.2 Significance of underlying malignant disease for potential pregnancy
Consensus-based recommendation 3.9.E55
Expert consensus
Strength of consensus +++
Patients with a possible genetic predisposition to develop cancer must be offered
genetic counselling.
Consensus-based recommendation 3.9.E56
Expert consensus
Strength of consensus ++
Disease-specific pregnancy risks must be discussed beforehand with patients who have
a history of oncologic disease.
1.2 Hematological factors
Not just pregnancy [32 ] but also ovarian stimulation [12 ] carried out in the context of fertility treatment is accompanied by an activation
of the female coagulation system. The changes which occur in this context include
increased coagulation and reduced fibrinolysis; they are comparable, in principle,
with changes which occur naturally during pregnancy [9 ], [11 ], [26 ] and are associated with an increased risk of thrombosis.
Basically, there are two areas which need to be taken into account when investigating
hematological factors: the importance of avoiding complications and aim to increase
the live birth rate (LBR). As regards avoiding complications, it appears to be important
whether the patient has a positive personal or familial history of VTE or not.
1.2.1 Diagnostic workup
Consensus-based recommendation 3.10.E57
Expert consensus
Strength of consensus +++
Asymptomatic women must not be screened for thrombophilia. Patients with a positive
personal or familial history of thromboembolic events should be investigated for thrombophilia
to evaluate their individual risk of thrombosis.
1.2.2 Treatment
Anticoagulation for the prophylaxis of thrombosis
Consensus-based recommendation 3.10.E58
Expert consensus
Strength of consensus +++
Asymptomatic women must not routinely be given anticoagulation during ART to prevent
thrombosis. If the patient has a positive personal or familial history of thrombophilia
or thromboembolic disease, the patientʼs management must be adapted to take account
of the patientʼs additional risk.
[Table 6 ] shows a possible approach to be taken during ovarian stimulation of a patient with
confirmed thrombophilia; this approach is similar to the management procedures used
for pregnant women. Patients who have had a prior thrombotic event should be managed
by an interdisciplinary team.
Consensus-based recommendation 3.10.E59
Expert consensus
Strength of consensus +++
No anticoagulation must be given if the sole purpose is to improve the pregnancy and
live birth rate.
Table 6 Possible approach in cases with confirmed maternal thrombophilia (taken from AWMF
2018, adapted from the ACOG bulletin as well as the German-language S3-guideline “Prophylaxis
Against Venous Thromboembolism (VTE)”, AWMF Guideline Register No. 003/001).
Clinical constellation
Possible approach
Confirmation of low-risk thrombophilia (heterozygous factor V Leiden mutation or prothrombin
mutation, protein C or S deficiency) with no prior history of thromboembolic events
(VTE)
Clinical monitoring or administration of heparin in prophylactic doses (if additional
risk factors are present)
Confirmation of low-risk thrombophilia (heterozygous factor V Leiden mutation or prothrombin
[G20210A] mutation, protein C or S deficiency) with positive familial history but no personal
history of thromboembolic events
Clinical monitoring or administration of heparin in prophylactic doses if additional
risk factors are present
Confirmation of low-risk thrombophilia (heterozygous factor V Leiden mutation or prothrombin
[G20210A] mutation, protein C or S deficiency) with prior history of thromboembolic events
but with no ongoing long-term anticoagulation
Clinical monitoring or administration of heparin in prophylactic doses
Confirmation of high-risk thrombophilia (antithrombin deficiency; combined heterozygous
status for prothrombin [G20210A] and factor V Leiden mutation; homozygous prothrombin and factor V Leiden mutation)
without prior history of thromboembolic events
Administration of heparin in prophylactic doses
Confirmation of high-risk thrombophilia (antithrombin deficiency; combined heterozygous
status for prothrombin [G20210A] and factor V Leiden mutation; homozygous prothrombin and factor V Leiden mutation)
with prior history of thromboembolic events but with no ongoing long-term anticoagulation
Administration of heparin in prophylactic, intermediate or adjusted doses
Prior history of two or more thromboembolic events with no long-term anticoagulation,
irrespective of thrombophilia status
Administration of heparin in prophylactic or therapeutic doses
Prior history of two or more thromboembolic events with long-term anticoagulation,
irrespective of thrombophilia status
Administration of heparin in therapeutic doses
1.3 Andrological diagnosis and treatment before starting assisted reproductive treatment
1.3.1 Andrological diagnostic workup
1.3.1.1 Indications for an andrological workup
Andrological examinations aim to identify possible causes of fertility disorders,
determine their severity and find out if they can be treated ([Fig. 1 ]).
Fig. 1 Indications for an andrological diagnostic workup. [rerif]
1.3.1.2 Guidelines and national regulations
The extent and type of required clinical andrological examinations have been specified
in the WHO manuals “WHO Manual for the Standardized Investigation, Diagnosis and Management
of the Infertile Male” [29 ] and the “WHO Manual for the Standardized Investigation and Diagnosis of the Infertile
Couple” [30 ]. In addition, there is also an international European guideline “Male Infertility”
by the European Association of Urology (EAU) [17 ].
Consensus-based recommendation 3.11.E60
Expert consensus
Strength of consensus +
Before starting any assisted reproductive treatment, the man must be examined by an
andrologist.
Consensus-based recommendation 3.11.E61
Expert consensus
Strength of consensus +++
Andrological examinations must include the manʼs personal and familial medical history
as well as the coupleʼs medical history and must include their sexual medical history,
a physical examination, an ejaculate analysis, and, if necessary, an ultrasound examination
of the scrotal organs as well as hormone, cytogenetic and molecular genetic examinations.
1.3.1.3 Lifestyle und male fertility
Overweight
Consensus-based recommendation 3.11.E62
Expert consensus
Strength of consensus ++
Overweight men should be advised to lose weight.
Nicotine
Consensus-based recommendation 3.11.E63
Expert consensus
Strength of consensus +++
Men must be advised to quit smoking.
Alcohol
Alcohol can have a negative effect on sperm quality through its impact on the pituitary-gonadal
axis and its direct injurious effect on the germinal epithelium and Leydig cells [3 ]. It is not possible to provide unambiguous data about a dose-response relationship.
Consensus-based recommendation 3.11.E64
Expert consensus
Strength of consensus +++
Men must be asked whether they take drugs and advised not to use drugs.
Consensus-based recommendation 3.11.E65
Expert consensus
Strength of consensus +++
Further investigations must be carried out if the andrological workup shows that the
patient has a history of taking anabolic steroids or physical examination or laboratory
tests show that the patient takes anabolic steroids.
Diet and sperm quality
The available studies indicate the necessity of a balanced and healthy diet [19 ].
Foods which are rich in omega-3 fatty acids, antioxidants such as vitamin E, vitamin
C, beta-carotene, selenium, zinc, cryptoxanthin or lycopene, other vitamins such as
vitamin D or folic acid and have low levels of saturated fatty acids appear to be
associated with a better sperm quality. A diet based on the consumption of fish, seafood,
chicken, cereals, vegetables and fruits, low-fat dairy products and low-fat milk appears
to be associated with a better sperm quality than a diet consisting predominantly
of ready meals, soya, potatoes, full-fat dairy products, cheese, coffee, alcohol,
sugary drinks and sweets [31 ].
The available studies do not provide evidence-based dietary recommendations for men
with involuntary childlessness.
1.3.1.4 Clinical examinations, diagnostic apparatus and laboratory workup in andrology
Significance of diagnostic procedures
A comprehensive workup is required if the patientʼs medical history, initial physical
examination or sperm analysis indicate abnormalities or if the couple is diagnosed
with idiopathic infertility or if infertility persists despite treatment of the underlying
gynecological factor. The evidence level for this approach is stated to be “moderate”.
Consensus-based recommendation 3.11.E66
Expert consensus
Strength of consensus +++
Examination of the ejaculate must be carried out in accordance with the 2010 WHO guidelines.
The quality of the tests determining sperm concentration, motility and morphology
must be verified and documented through regular participation in external and internal
quality assurance programs.
Microbiological examinations
Consensus-based recommendation 3.11.E67
Expert consensus
Strength of consensus +++
Microbiological examination of the ejaculate must be carried out if > 1 × 106 /ml peroxidase-positive cells are detected in the ejaculate.
Examination of post-orgasmic or post-ejaculatory urine sediment
Consensus-based recommendation 3.11.E68
Expert consensus
Strength of consensus +++
Post-ejaculatory urine sediment must be examined if there is no ejaculation despite
orgasm or the ejaculate volume is significantly decreased and the patientʼs medical
history indicates the possibility of partial or complete retrograde ejaculation. It
is important to first exclude problems in obtaining the ejaculate.
Endocrine examinations
The importance of investigating basal hormone levels to evaluate fertility is because
of the information this workup can provide about possible causes of reduced sperm
quality and whether these causes are treatable ([Fig. 2 ]).
Consensus-based recommendation 3.11.E69
Expert consensus
Strength of consensus +++
The endocrine workup of men with involuntary childlessness must also address any issues
in the patientʼs medical history, his physical examination and the findings of an
examination of the ejaculate.
Consensus-based recommendation 3.11.E70
Expert consensus
Strength of consensus +++
The basic endocrine examination of male patients must include FSH and testosterone;
further endocrine tests will be necessary if the basic examination shows abnormal
findings.
Consensus-based recommendation 3.11.E71
Expert consensus
Strength of consensus +++
Further diagnostic investigations must be carried out if the patientʼs medical history
or any findings during his physical examination indicate possible hypogonadism.
Fig. 2 Diagnostic information obtained from examinations of the basal endocrine system in
the context of further diagnostic examinations. [rerif]
Secondary hypogonadism is particularly important from a therapeutic point of view.
Hypothalamic damage with reduced secretion of GnRH leading to a lack of stimulation
of the pituitary gland or dysfunction of the pituitary gland itself results in a lack
of stimulation of the testes due to low gonadotropin levels. Pituitary gland damage
may be caused by pituitary tumors such as prolactinoma. Kallmann syndrome and congenital
hypogonadotropic hypogonadism are typical examples of hypothalamic damage. In cases
with decreased LH and FSH levels, it may be necessary to specifically re-examine the
patientʼs medical history (use of testosterone or anabolic steroids?). In addition,
prolactin levels should be determined and further diagnostic tests should be carried
out if prolactin levels are increased (e.g. diagnostic imaging, investigation of other
pituitary hormones).
The GnRH test (LHRH test) or GnRH pump test are useful to differentiate whether reduced
gonadotropin serum concentrations are due to hypothalamic or pituitary disorders.
An increase in gonadotropin levels after external GnRH stimulation indicates the presence
of a hypothalamic disorder; if there is no increase in gonadotropin serum concentrations
after external GnRH stimulation then the cause of the disorder is located in the pituitary
gland.
Genetic diagnostic workup
See chapter on Genetic Factors.
Diagnostic testicular biopsy
If the findings on testicular ultrasound result in a diagnosis of testicular microlithiasis
or a suspicion of a testicular pathology in a patient with oligozoospermia, then a
diagnostic testicular biopsy may be indicated, particularly if additional risk factors
are present (undescended testicles, testicular tumor) [34 ]. Infertile men have a significantly higher incidence of germ cell tumors compared
to the general male population [5 ], [28 ]. Multiple sampling should always be done during diagnostic testicular biopsy to
increase diagnostic certainty [13 ], [18 ]. Different scoring systems are available to evaluate spermatogenesis [7 ].
Consensus-based recommendation 3.11.E72
Expert consensus
Strength of consensus +++
Purely diagnostic testicular biopsies must not be carried out if there is no suspicion
of testicular pathology.
Consensus-based recommendation 3.11.E73
Expert consensus
Strength of consensus +++
A histological biopsy must be carried out when sampling testicular tissue for spermatozoa
extraction to obtain more information about the cause of azoospermia/disordered spermatogenesis
and to detect any testicular germ cell neoplasia in situ (GCNIS).
1.3.2 Causes and treatment approaches for male infertility disorders
Consensus-based recommendation 3.11.E74
Expert consensus
Strength of consensus +++
Treatable disorders should be treated before deciding that ART is indicated. Any gynecological
findings must be carefully considered before making the decision to treat andrological
factors ([Fig. 3 ]).
Fig. 3 Andrological treatment algorithm. [rerif]
Consensus-based recommendation 3.11.E75
Expert consensus
Strength of consensus +++
If secondary hypogonadism with azoospermia is present, causal therapy must be attempted
before carrying out testicular biopsy with TESE/ICSI or ICSI for cryptozoospermia
or severe oligozoospermia, unless the gynecological findings require a different chronological
approach.
Consensus-based recommendation 3.11.E76
Expert consensus
Strength of consensus +++
The surgical treatment for azoospermia must be guided by the cause of the azoospermia
and must differentiate between obstructive and non-obstructive causes.
Consensus-based recommendation 3.11.E77
Expert consensus
Strength of consensus +++
Depending on the cause of the obstructive azoospermia, the patient must be offered
reconstructive microsurgery or surgery to obtain spermatozoa. Priority should be given
to reconstructive surgery rather than procedures purely designed to extract sperm.
Consensus-based recommendation 3.11.E78
Expert consensus
Strength of consensus ++
A genetic workup must be done to obtain a differential diagnosis for non-obstructive
azoospermia before carrying out surgical sperm extraction, as this could have consequences
for the success of surgical treatment (see Chapter 3.12.1.1).
Consensus-based recommendation 3.11.E79
Expert consensus
Strength of consensus +++
Surgical sperm extraction procedures must be combined with the option of sperm cryopreservation.
Consensus-based recommendation 3.11.E80
Expert consensus
Strength of consensus +++
Endocrine disorders associated with azoospermia must be treated prior to performing
surgical sperm extraction, if the pathology permits.
Consensus-based recommendation 3.11.E81
Expert consensus
Strength of consensus +++
Microsurgical or multifocal testicular tissue retrieval for TESE must be carried out
in patients with non-obstructive azoospermia.
Infections and inflammations of the genital tract
Various aspects must be borne in mind when investigating potential urogenital infections
in men with involuntary childlessness prior to starting ART:
the impact of infections on sperm quality and male fertility
transmission of the infection to the female partner
contamination of culture media and oocytes during the ART procedure
Consensus-based recommendation 3.11.E82
Expert consensus
Strength of consensus ++
Relevant bacterial infections of the seminal ducts must be treated with antibiotics
(both partners must be treated, if necessary).
1.3.2.1 Immunological infertility
Consensus-based recommendation 3.11.E83
Expert consensus
Strength of consensus +++
The confirmation of sperm autoantibodies in the ejaculate is an immunological infertility
factor, and ART may be indicated.
1.3.3 Reproductive biology and diagnostic and therapeutic aspects before starting
assisted reproductive treatment
1.3.3.1 Significance of sperm DNA fragmentation assay
Consensus-based statement 3.11.S1
Expert consensus
Strength of consensus +++
Although the analysis of DNA fragmentation in spermatozoa could potentially be a useful
clinical biomarker, the conclusive predictive value of this test for IVF and/or ICSI
treatment is still unclear. Nevertheless, carrying out sperm DNA fragmentation analysis
in addition to standard sperm analysis to determine sperm DNA integrity can lead to
a more comprehensive understanding of the manʼs reproductive health.
1.3.3.2 Significance of sperm enrichment procedures
Consensus-based statement 3.11.S2
Expert consensus
Strength of consensus +++
A sperm enrichment procedure may provide information about the behavior of the ejaculate
sample in the female genital tract.
Consensus-based recommendation 3.11.E84
Expert consensus
Strength of consensus +++
A sperm enrichment procedure must be carried out before every ART to obtain a better
assessment of the necessary therapy.
1.3.3.3 Procedure for immotile sperm
Consensus-based statement 3.11.S3
Expert consensus
Strength of consensus +++
It is useful to determine the percentage of vital but immotile sperm beforehand. It
may serve as a diagnostic analysis for further treatment options, e.g. TESE before
starting ART treatment or the use of non-depleting vitality tests on the day of ICSI.
Consensus-based recommendation 3.11.E85
Expert consensus
Strength of consensus +++
In patients with immotile sperm, a diagnostic vitality test to determine the number
of vital but immotile sperm should be carried out before starting ART.
1.4 Genetic factors
1.4.1 Diagnosing genetic factors
Genetic disorders (chromosome changes and monogenic disorders) are responsible for
around 10 – 20% of male and 5 – 10% female cases of infertility or subfertility. Before
starting ART, the patientʼs detailed personal and familial medical history should
be taken, for example in the context of genetic counselling, with a view to identifying
potential hereditary disorders. Particular attention must be paid to a possible familial
aggregation of possible genetic developmental disorders, infertility or hormonal imbalances.
If there are indications of an underlying genetic disease in the family, it is usually
necessary to carry out a molecular genetic workup of an affected person before persons
at risk can be tested. [Fig. 4 ] shows an algorithm for the genetic workup of couples before starting assisted reproductive
treatment.
Consensus-based recommendation 3.12.E86
Expert consensus
Strength of consensus +++
A detailed personal and familial medical history of the couple wanting to have children
must be taken with a view to identifying potential genetic risk factors. Genetic counselling
must be offered by a genetic specialist in accordance with national guidelines prior
to carrying out a genetic workup.
Fig. 4 Algorithm for the genetic workup of couples before starting ART. [rerif]
1.4.1.1 Male genetic factors
According to the WHO guideline [3 ], no genetic testing is required if the spermatogenesis disorder has a known non-genetic
cause (prior chemotherapy, use of anabolic steroids).
If an additional genetic workup is required, it is useful to differentiate between
non-obstructive azoospermia or oligozoospermia and obstructive azoospermia:
a Non-obstructive disorders of spermatogenesis
i. Y-chromosomal microdeletions
Y-chromosomal microdeletions are the second most common genetic cause of disorders
of spermatogenesis and play a significant role in the chance of success of testicular
biopsies. Y-chromosome microdeletions are found in less than 2% of infertile men in
Germany and Austria. The overwhelming majority, accounting for around 80% of cases,
are AZFc deletions which lead to a variable phenotype. Most men with AZFa (0.5 – 4%),
AZFb (1 – 5%) or AZFbc (1 – 3%) deletions have Sertoli cell-only syndrome. The probability
that testicular biopsy will be able to retrieve sperm from these patients is extremely
low [20 ].
Consensus-based recommendation 3.12.E87
Expert consensus
Strength of consensus +++
After excluding other causes, cases with non-obstructive azoospermia must and of cases
with severe oligozoospermia (< 5 million/ml) should be analyzed for AZF microdeletions
(AZFa, b, c).
ii. Chromosomal changes
In addition to maldistribution of sex chromosomes, balanced chromosome translocations
may also result in disordered spermatogenesis. This increases the percentage of men
with chromosomal changes who only have a fertility disorder and are otherwise healthy.
The probability that men undergoing fertility treatment have chromosomal abnormalities
increases with decreasing sperm counts ([Table 7 ]); compared to normal populations, the probability is higher, even for men with normal
sperm counts. It is considered a subfertility factor.
Consensus-based recommendation 3.12.E88
Expert consensus
Strength of consensus +++
Chromosome analysis should be carried out in cases with non-obstructive azoospermia
or severe oligozoospermia (< 5 million/ml) after excluding other causes.
Table 7 Percentage of men with abnormal chromosome findings according to sperm analysis results
[14 ].
Sperm analysis results
Percentage of patients with chromosomal abnormalities (confidence interval)
Azoospermia (n = 1599)
15.4 (13.6 – 17.2%)
Oligozoospermia < 1 million/ml (n = 539)
3.0 (1.5 – 4.4%)
Oligozoospermia > 1 – 5 million/ml (n = 475)
2.1 (0.8 – 3.4%)
Oligozoospermia > 5 – 10 million/ml (n = 879)
3.5 (2.3 – 4.7%)
Oligozoospermia > 10 – 20 million/ml (n = 808)
1.1 (0.4 – 1.8%)
Normozoospermia > 20 million/ml (n = 729)
2.9 (1.7 – 4.1%)
Normal sperm count
0.3 – 0.5%
iii. Monogenic causes of disorders of spermatogenesis
As the causes of non-obstructive disorders of spermatogenesis in more than 80% of
affected men are still unknown, an intensive search for new candidate genes is underway.
Given the number of available genetic analyses of monogenic disorders of spermatogenesis,
it is important to take into account that confirmed disorders currently do not influence
the procedure or outcome of ART. This assessment may change in future if, depending
on the genetic cause, targeted treatments become available. Further scientific studies
are necessary to better understand the importance of individual genetic mutations
for spermiogenesis.
Consensus-based recommendation 3.12.E89
Expert consensus
Strength of consensus +++
Genetic analysis may be offered if there is a suspicion of a rare monogenic cause
of disordered spermatogenesis.
iv. Obstructive azoospermia
The basis for this diagnosis is intact spermatogenesis in the testicular tissue, a
finding which offers good chances of success for ART with TESE/ICSI. Around 2% of
men with azoospermia have anomalies of Wolffian duct derivatives, usually in the form
of a CBAVD, more rarely taking the form of a CUAVD or bilateral epidydimal obstruction.
At least one CFTR mutation is found in around 80% of patients with CBAVD and the cause is assumed to
be CF-associated disease.
Consensus-based recommendation 3.12.E90
Expert consensus
Strength of consensus +++
After excluding other causes, the CTFR gene must be analyzed if there is a suspicion
of obstructive azoospermia. The analysis must cover all relevant pathogenic mutations,
including TG-T repeats in CFTR intron 8; complete sequencing must be carried out if
only a heterozygous mutation is identified.
Consensus-based recommendation 3.12.E91
Expert consensus
Strength of consensus +++
If the findings of CFTR analysis in a patient with obstructive azoospermia are normal, the ADGRG2 gene should be analyzed.
b. Endocrine disorders
If endocrine abnormalities are present, differentiating between hypo- or hypergonadotropic
hypogonadism will be important for the genetics.
i. Hypergonadotropic hypogonadism
Primary testicular functional failure is found primarily in men with Klinefelter syndrome;
it is the most common genetic cause of male infertility in men with azoospermia, occurring
in about 14% of men with azoospermia. Around 80% have a 47,XXY karyotype, while about
20% have higher grade aneuploidies, mosaicism (46,XX/47XXY) or structurally changed
X chromosomes [33 ].
Consensus-based recommendation 3.12.E92
Expert consensus
Strength of consensus +++
After other causes have been excluded, chromosome analysis must be carried out in
men with hypergonadotropic hypogonadism.
ii. Hypogonadotropic hypogonadism
The incidence of congenital hypogonadotropic hypogonadism (CHH) is around 1 in 4000 – 10 000
men, making it about 3 to 5 times more common in men than in women [10 ]. Numerous genes have been identified as possible causes of CHH, accounting for 40 – 50%
of cases [8 ]; the X chromosome KAL1 gene is the most important of these genes and accounts for
around 10% of cases.
Consensus-based recommendation 3.12.E93
Expert consensus
Strength of consensus +++
After excluding exogenous causes, genetic analysis of CHH genes may be carried out
in men with congenital hypogonadotropic hypogonadism (CHH).
1.4.1.2 Female genetic factors
Ovulatory dysfunction
Oligorrhea or amenorrhea (ovulatory dysfunction) is present in around 40% of women
with fertility disorders [24 ]. The decisive factor is maternal age, and maternal age also determines the success
of ART with the patientʼs own oocytes, while primarily genetic causes are comparatively
rare. Above the age of 40 – 45 years, the overwhelming majority of oocytes are aneuploid,
meaning that only a small percentage will successfully develop into a blastocyst and
implant [1 ], [15 ].
a. Hypergonadotropic hypogonadism
Around 10 – 13% of affected women have gonosomal aberrations such as a 45,X or 47,XXX
cell line or a structurally changed X chromosome, meaning that chromosome analysis
is indicated if other causes of infertility have been ruled out [27 ].
Consensus-based recommendation 3.12.E94
Expert consensus
Strength of consensus +++
After excluding other causes, chromosome analysis must be carried out in women with
hypergonadotropic hypogonadism.
Premutations in the FMR1 gene (CGG repeats of 55 – 200) often lead to primary or secondary ovarian insufficiency;
if they are passed on to children, they have a high probability of expanding into
a full mutation. Full mutations of FMR1 (CGG repeats of more than 200) can result in mental disability (fragile X syndrome,
fra [X] syndrome), particularly in males; the mutations are not associated with ovarian
insufficiency. Around 2% of Caucasian women with primary ovarian insufficiency and
no familial aggregation and 10 – 15% of Caucasian women with familial aggregation
have a premutation of the FMR1 gene [25 ]; given the associated risk of a child with fragile X syndrome, this finding may
have a significant impact on subsequent family planning.
Consensus-based recommendation 3.12.E95
Expert consensus
Strength of consensus +++
Genetic analysis of CGC repeats in the FMR1 gene must be carried out in women with primary or premature ovarian insufficiency
after other causes of infertility have been excluded.
b. Hypogonadotropic hypogonadism
The incidence of congenital hypogonadotropic hypogonadism (CHH) is about 1 in every
30 000 – 40 000 women, making it a very rare entity. While Kallmann syndrome (KS),
in which the sense of smell is diminished or absent, is formally differentiated from
normosmic hypogonadotropic hypogonadism (nHH), in practice the transition is fluid.
At present, 35 – 40% of the molecular causes of congenital hypogonadotropic hypogonadism
are known and can be traced back to mutations in at least 20 genes [21 ]. The exogenous administration of sex hormones, gonadotropins or GnRH analogs represents
the only treatment option for all known disorders [8 ].
Consensus-based recommendation 3.12.E96
Expert consensus
Strength of consensus +++
After excluding exogenous causes, genetic analysis of CHH genes may be carried out
in women with congenital hypogonadotropic hypogonadism (CHH).
c. Hyperandrogenism
AGS is the most important underlying genetic disease leading to hyperandrogenism.
The most common form is a 21-hydroxylase deficiency caused by autosomal recessive
mutations in the CYP21A2 gene. Endocrine treatment is guided by the underlying enzyme defect and the pathogenicity
of confirmed mutations. Prenatal treatment to prevent virilization in female fetuses
with a risk of AGS due to 21-hydroxylase deficiency was still classified as an experimental
therapy at the time of compiling the guideline, and the benefits and risks of this
treatment should therefore be carefully weighed up in each individual case [2 ].
Consensus-based recommendation 3.12.E97
Expert consensus
Strength of consensus ++
A genetic workup must be carried out if there is a suspicion of adrenogenital syndrome.
Balanced chromosome changes
Structural chromosome aberrations are also a relevant cause of infertility in women,
even if these abnormalities are not apparent during gynecological examinations. A
French study reported that the female partners of infertile men had an increased percentage
of balanced translocations (factor 4,5) or inversions (factor 16) which was comparable
to that of their investigated male partners (n = 3208 patients) [16 ]. The percentage of women with chromosome changes was inversely correlated with their
partnerʼs sperm pathology.
Consensus-based recommendation 3.12.E98
Expert consensus
Strength of consensus +
After excluding other causes of infertility, a chromosome analysis of both partners
should be carried out.
1.4.2 Treatment of genetic factors
Consensus-based recommendation 3.12.E99
Expert consensus
Strength of consensus +++
If structural chromosome changes are confirmed in one of the partners, the couple
must be informed about the options for polar body diagnosis and preimplantation genetic
diagnosis as well as about prenatal diagnostic examinations (invasive and non-invasive
prenatal options for a diagnostic workup).
