Male infertility is the result of a variety of diseases and/or factors, usually divided into pre-testicular, testicular and post-testicular factors depending on the reproductive link affected, but there are still up to 60%-75% of patients for whom no cause can be found (clinically known as idiopathic male infertility).
I. Pre-testicular factors: Usually endocrine in origin, the patient’s fertility is impaired secondary to hormonal imbalance in the body.
1. Thalamic disorders:
(1) gonadotropin deficiency: Kallmann’s syndrome (Kallmann’s syndrome).
(2) Selective luteinizing hormone (LH) deficiency.
(3) selective follicle stimulating hormone (FSH) deficiency.
(4) congenital hypogonadotropic syndrome.
2. Pituitary disorders.
(1) Pituitary insufficiency.
(2) hyperprolactinemia.
3. Endogenous or exogenous hormone abnormalities.
(1) Excess estrogen and/or androgens.
(2) Excessive glucocorticoids.
(3) hyper- or hypothyroidism.
Testicular factors
1. Congenital abnormalities
(1) Chromosomal or genetic abnormalities.
(2) Cryptorchidism.
(3) Androgen dysfunction: mainly androgen insensitivity and peripheral androgen resistance.
(4) Other less common syndromes.
2. gonadotoxins Commonly include radiation, drugs, food, life and work environment factors, etc.
3. systemic diseases commonly causing infertility systemic diseases including renal failure, cirrhosis and hepatic insufficiency, sickle cell disease, etc.
4, infection (orchitis) after puberty mumps 30% combined with orchitis, often unilateral, bilateral incidence of 10% to 30%, testicular atrophy is the most common serious consequences
5, testicular trauma and surgery testicular trauma can lead to testicular atrophy in addition to stimulating an abnormal immune response, both of which can lead to infertility. Medical injury to testicular vessels and vas deferens can also lead to infertility
6, vascular factors varicocele, the incidence of which is nearly 40% in infertility patients
7, testicular torsion can cause ischemic damage to the testis, the degree of injury is related to the degree and duration of ischemia, and torsion on one side can cause histological changes in the opposite testis.
8,Immunological factors, due to their own anti-sperm antibodies positive lead to male infertility.
Third, post-testicular factors
1, vas deferens obstruction vas deferens obstruction, is one of the important causes of male infertility, obstructive azoospermia in male infertility patients for 7% to 10%.
(1) Congenital obstruction.
(2) Acquired obstruction: mainly reproductive system infection, vasectomy, obstruction of the ejaculatory orifice due to medically induced vasectomy injury and infection, etc. (2) Acquired obstruction: mainly due to reproductive system infection, vasectomy, medical vas deferens injury and infection.
(3) Functional obstruction: any factor that interferes with the nerve conduction in the vas deferens and bladder neck can lead to non-ejaculation or retrograde ejaculation, with common causes such as nerve injury and taking certain drugs.
2. sperm function or motility disorders.
(1) Cilia immobility syndrome.
(2) maturation disorders.
3, immune infertility 2% to 10% of infertility is related to immune factors, anti-sperm antibody (antisperm antibody, AsAb) is an important cause of immune infertility. Common causes include testicular trauma, torsion, biopsy, infection or obstruction of the vas deferens, post-anastomotic surgery, etc.
4, infection 8% to 35% of infertility is related to infection of the male reproductive tract, mainly infection leading to obstruction of the vas deferens, anti-sperm antibody formation, bacteriospermia, leukocytosis of semen and abnormal seminal plasma
5, sexual intercourse or ejaculatory dysfunction hypersexuality, erectile dysfunction and ejaculatory dysfunction are common causes of male infertility; anatomical abnormalities such as hypospadias cause infertility due to ejaculation of semen too far from the cervix; diabetes, inflammation of the bladder urethra, abnormal bladder neck muscles, surgery or trauma injury to the nerves can lead to non-ejaculation or retrograde ejaculation; bad sexual habits such as too frequent intercourse, use of lubricants, etc. can also Bad sexual habits such as frequent intercourse and use of lubricants can also affect fertility.
IV. Idiopathic causes
Idiopathic infertility refers to male infertility where no clear cause can be found, and the link affecting reproduction may involve one or more links in the pre-testis, testis, or post-testis. The current tendency is to be associated with genetic or environmental factors, etc.