Investigations
1st investigations to order
sperm concentration
Test
Oligozoospermia (<16 million sperm/mL) may indicate a disruption of spermatogenesis at many different levels.[33]
Result
<16 million sperm/mL
sperm motility
Test
May indicate the presence of anti-sperm antibodies, sperm necrosis, flagellar defects, or toxic exposure.
Result
<42% motile spermatozoa
sperm morphology
Test
Determines whether the sperm has successfully completed spermiogenesis, and is a measure of sperm fitness for fertilisation and conception.
Result
<4% normal forms
seminal fluid parameters
Test
Low volume, decreased pH, or aspermia indicates reproductive tract disorders and should be followed up with prostate examination, transrectal ultrasound, and/or post-ejaculatory urine analysis.
The specimen may be assayed for the presence of fructose to determine whether the seminal vesicles are contributing.
Result
poor liquefaction; low ejaculate volume (<1.4 mL); decreased seminal pH; presence of fructose; increased leukocyte count
Investigations to consider
sperm viability
Test
Histological test using eosin and nigrosin, referred to as the Live/Dead assay.
Greater than 46% sperm necrosis is often caused by anti-sperm antibodies, but may be due to idiopathic causes or toxic exposure.[33]
Result
>46% sperm necrosis
sperm membrane function
Test
Determines cell viability by using a hypo-osmotic solution to detect the osmoregulatory capacity of the sperm membrane.
Result
>40% reacted sperms
hormonal assays
Test
Measure follicle-stimulating hormone (FSH), luteinising hormone (LH), free and total testosterone, estradiol, sex hormone-binding globulin, and prolactin levels. Albumin may be obtained for calculation of bioavailable testosterone.
Thyroid-stimulating hormone (TSH) can be ordered in cases of failed IVF among men >40 years or if there is association with erectile dysfunction.[36][37][38]
Result
abnormal levels depend on the laboratory standard
MRI of the pituitary and hypothalamus
Test
MRI of the brain is indicated to rule out pituitary or hypothalamic tumours or other disorders in the setting of hypogonadotrophic hypogonadism (low LH and low testosterone).
Result
lesion in the pituitary or hypothalamus
colour flow Doppler imaging
Test
May be used in conjunction with the physical examination to diagnose a low-grade varicocele.
Result
presence of a varicocele
post-ejaculation urine testing for retrograde ejaculation
Test
Performed by collecting a urine sample directly following the collection of any antegrade ejaculation. If positive, retrograde ejaculation is present.
Result
presence of semen
genetic analysis
Test
Karyotype analysis diagnoses Klinefelter syndrome and polymerase chain reaction for microdeletions of the Y chromosome.[15] Indicated with concentrations <5 million/mL and suspected aetiology of spermatogenic dysfunction.[34] Additionally indicated in the setting of recurrent pregnancy loss.
Mutations in the CFTR gene are present in up to 80% of men with congenital bilateral absence of vas deferens (CBAVD).[24]
Result
chromosomal abnormalities; CFTR gene mutation
sperm DNA assays
Test
Suggested tests are the sperm chromatin structure, terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick-end labelling, or sperm chromatin dispersion test. Cut-off values that predict success with insemination remain controversial.[40]
DNA damage may be a cause of infertility, recurrent pregnancy loss, or recurrent IVF failures.[24][41][42]
Result
must be reported with internal control samples; normal range should be set by individual laboratories
anti-sperm antibody (ASA) serology
Test
Do not perform anti-sperm antibody (ASA) testing in the initial evaluation of male infertility.[24] While ASA testing may have a role in confirming obstruction, only consider it if the results will affect management of the patient.[24]
Determines whether antibodies that are targeting sperm surface antigens have developed in the male reproductive tract.
Result
IgG, IgM, and IgA titers are reported with laboratory control values
acrosome reaction test
Test
Determines the ability of acrosome (anterior part of the sperm head) to successfully penetrate the outer coating of the egg.
The assay may determine whether there is a propensity for premature acrosome reaction. The assay should be run in conjunction with a simultaneous Live/Dead stain to be accurate.
Result
must be reported with internal control samples; normal range should be set by individual laboratories
sperm longevity test
Test
Aids in diagnosis of poor sperm survivability after ejaculation.
Result
gradual decline in sperm motility is seen over a 6- to 12-hour period with at least 4 time points included; sperm motility should be at least one half of initial value at 12 hours in washed sperm suspension
electron microscopy
Test
Requested when sperm motility is abnormal and microtubule dysfunction or nuclear/chromatin abnormalities are suspected.
Result
microtubule abnormality
testicular biopsy
Test
Diagnostic testicular biopsies are not routinely performed because laboratory and clinical findings may accurately predict obstructive versus non-obstructive aetiology.[20]
Biopsy should be performed in conjunction with an experienced andrologist to assess the wet preparation of tissue for viable sperm, with a portion of the sample sent for histopathological evaluation.
A follicle-stimulating hormone (FSH) >7.6 mIU/mL and testicular longitudinal axis (TLA) <4.6 cm predicts an 89% likelihood of spermatogenic dysfunction, while an FSH <7.6 mIU/mL and TLA >4.6 cm predicts a 96% likelihood of obstructive aetiology.[43]
Microdissection testicular sperm extraction (micro-TESE) is recommended in males with non-obstructive azoospermia who are undergoing sperm retrieval (and subsequent cryopreservation for use with ICSI).[24] Micro-TESE allows examination of multiple regions of testicular tissue.
Result
arrested spermatogenesis
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