I. Definition of oligozoospermia
Normal semen: total number of sperm, proportion of forward motile sperm (PR), normal form sperm equal to or above the lower limit of the reference value.
Oligospermia: Total sperm count (single ejaculation) is less than the lower limit of the reference value.
Weak spermatozoa: sperm motility is below the lower limit of the reference value.
Oligozoospermia: abnormalities in both of the above variables, with two prefixes available.
Severe oligospermia: Severe oligospermia is defined as a sperm density between 1 and 5 x 106/ml.
Severe weak spermatozoospermia: there is no clear definition.
Occult spermatozoospermia: no sperm are seen on microscopic examination and sperm can be detected by centrifugal sedimentation.
Note: The above diagnosis must be determined by more than two semen tests, and the interval between the two tests depends on the clinical situation. Semen test especially to assess the sperm count abstinence time should not be less than 48 hours; to assess sperm vitality, abstinence time should not exceed 7 days.
Second, the diagnosis of oligozoospermia
Oligozoospermia is the most common type of male infertility, but a reasonable diagnosis is also a clinical challenge. A detailed history, physical examination, laboratory tests and necessary special tests are necessary to clarify the cause and diagnosis, and to assess what options are available to the patient to obtain offspring.
1. Medical history
The main reason for emphasizing history taking in semen testing, especially in weak spermia spermia, is to help diagnose the disease. One quarter of patients with oligozoospermia can be diagnosed through history information, which can also help determine prognosis and decide on treatment strategies. These include: ① history of secondary fertility; ② time of natural infertility; ③ previous infertility tests and treatment; ④ history of systemic diseases; ⑤ medical influences: drug factors, history of surgery; ⑥ urinary tract infections and sexually transmitted diseases; ⑦ epididymitis, orchitis and testicular trauma; ⑧ other factors.
2. Physical examination
The content mainly includes detailed examination of bilateral testicular volume, epididymis, vas deferens and spermatic veins, rectal finger examination, etc. The volume of the testes should be measured with a testicular volume measurement model.
3.Semen analysis and washing treatment
Semen analysis includes the analysis of sperm and seminal plasma characteristics and parameters. The methods and standards used should be in accordance with the WHO Manual of Laboratory Tests for Human Semen and Sperm Processing (CUP, 5th edition, 2009), and internal and external laboratory quality control must be strengthened.
Anti-sperm antibody (AsAb) testing is recommended using the immunobead test (IBT) method, and the criteria for a positive reading are shown in the attached table. It is recommended to routinely test for malformation rate, and the use of modified Papanicolaou (Papanicolaou) and Diff-Quik, Shorr stain methods is recommended for staining judgments. If the normal sperm morphology rate is less than 5%, the success rate of IUI is low and the fertilization rate of standard IVF is low or even completely non-fertilized. If the malformation rate exceeds 99%, especially in round-headed spermatozoa due to acrosome defects, the fertilization rate and pregnancy rate are lower even with ICSI.
Sperm washing treatment: If the sperm recovery rate is too low, IUI is not recommended if the forward moving sperm is less than 5 million after washing.
4.Selective tests
(1) Sex hormone test
Sex hormone testing is not commonly used in the diagnosis of oligozoospermia, and is only performed when certain special needs arise. For sperm density less than 10×106/ml, serum testosterone (T) and follicle stimulating hormone (FSH) screening is performed. If the testosterone value is less than 300 ng/dl, free T, luteinizing hormone (LH), and prolactin (PRL) are also measured.
(2) Karyotype analysis and Y chromosome microdeletion detection
Sex chromosome and autosome karyotype analysis and Y chromosome microdeletion test should be performed for all men with sperm density below 5-10×106/ml and no fertility.
(3) Ultrasound examination
Doppler ultrasonography can also be used as an alternative method to diagnose varicocele. Scrotal ultrasound should be routinely performed for scrotal masses. Transrectal ultrasound is required in some patients with semen volumes less than 1.5 ml.
(4) Blood, urine and prostate fluid tests
Blood analysis can help to detect certain systemic diseases that may affect fertility. Routine urinalysis is useful for clinical diagnosis and treatment.
(5) Sperm function tests
Sperm acrosome reaction (calcium carrier or zona pellucida induced acrosome reaction), abnormal zona pellucida binding test, ICSI is recommended, and sperm DNA fragmentation index (DFI) has some reference value to determine the natural pregnancy rate and the success rate of IUI, the success rate of IUI in patients with DFI over 30% is low.
(6) Assessment of partner fertility
For mild to moderate oligozoospermia and critical oligozoospermia must pay attention to the examination and treatment of the spouse.
Third, the treatment view of oligozoospermia
For oligozoospermia, there is a lack of effective cause-specific treatment and evidence-based medical and surgical measures, and the application of assisted reproductive technology (ART) for the treatment of oligozoospermia has been widely used.
Currently only endocrine factors such as hypogonadotropic hypogonadism and hyperprolactinemia can be effectively treated pharmacologically with the application of hCG and hMG for hypogonadotropic hypogonadism and bromocriptine or capsaicin for hyperprolactinemia. Some of the combined low semen volume is diagnosed as ejaculatory duct obstruction for surgical treatment.
In the case of oligozoospermia, especially in weak spermatozoa, detection of antisperm antibodies is clinically relevant and ART is recommended if antisperm antibodies are positive; steroid hormone therapy is not recommended due to side effects such as femoral necrosis. 40% of oligozoospermia has an unknown cause and half of those with a cause have no targeted treatment plan. For example, accessory gland infections (mainly prostatitis), defined as more than 1 million white blood cells per milliliter of semen, have no definitive impact on fertility and are not treated with antibiotics in the absence of other clinical symptoms. Varicocele accounts for about 23% of infertile men, however, the efficacy of varicocele surgery for oligozoospermia remains controversial, and the procedure does not significantly improve pregnancy rates, especially in patients with low sperm density.
Empirical treatments attempting to improve semen quality and increase pregnancy rates are still widely used in clinical practice. For decades, many drugs have been applied to treat unexplained oligospermia, such as androgens, gonadotropins, bromocriptine, antioxidants such as vitamin E, pancreatic kinase, adrenocorticotropic hormone, carnitine; and herbal medicines. Anti-estrogenic drugs such as tamoxifen alone or in combination with androgens may be effective in some patients with oligozoospermia. α-blockers and mast cell blockers have also been used in unexplained oligozoospermia, but there is still a lack of evidence-based evidence. Chinese medicine is also widely used in clinical practice, but it is necessary to grasp the indications and identify the evidence for its use, and not to abuse kidney tonics.
Due to the lack of targeted and effective treatments, improving the fertility status of the partner has become the first-line treatment option to improve pregnancy rates. It is important to pay attention to the diagnosis and treatment of female infertility factors, especially in patients with mild oligozoospermia. Idiopathic oligozoospermia is recommended to start with intrauterine insemination (IUI) and if 3-6 cycles fail then in vitro fertilization-embryo transfer (IVF-ET), single sperm intracytoplasmic injection (ICSI).