Male infertility refers to a couple who have normal sexual life after marriage, without using any contraception, and whose wife is infertile due to the male partner. In view of the fact that about 80% of normal couples can achieve pregnancy within 1 year and 90% within 2 years after marriage without contraception, the time limit for cohabitation after marriage was once limited to 2 years. Later, the World Health Organization defined the time limit of cohabitation after marriage for male infertility as 1 year, in order to promote early diagnosis and treatment of infertility. If a couple has not conceived after 1 year of marriage, they should actively go to the hospital for consultation and examination.
Male infertility is divided into absolute infertility and relative infertility according to clinical manifestations; primary and secondary infertility according to the course of the disease. Infertility is a common disease, according to the World Health Organization estimates, in the reproductive age about 8% of couples suffering from infertility disorders, according to this projection of the world about 50-80 million people suffering from infertility problems, and the trend is increasing year by year. The proportion of male causes of infertility is generally not less than 50%, indicating that men and women, as in the case of infertility disorders, have an equally important position in the diagnosis and treatment of infertility, the couple should be considered as a whole.
I. Etiology
The etiology of male infertility can be classified in a variety of ways due to different authors. After simplification, they can generally be divided into three main categories.
1, pre-testicular causes
Pre-testicular lesions: refers to lesions in the male gonadal axis above the testes, mainly in the hypothalamus and pituitary gland, which is known as endocrine infertility. For example, Kallmann syndrome, delayed puberty, pituitary gigantism, dwarfism, etc. Clinical manifestations are hypopituitarism, low FSH and LH (or LH alone) and serum testosterone concentrations. Spermatogenic dysfunction, small and soft testes, lack of secondary sexual characteristics or impotence.
(1) Kallmann’s syndrome and idiopathic hypogonadotropic hypogonadism: Kallmann’s syndrome is a syndrome of hypogonadotropic hypogonadism with or without olfactory disturbance, with clinical manifestations of hypogonadism due to impaired secretion of gonadotropin-releasing hormone (GnRH), as patients all have testicular The clinical manifestation of hypogonadism is due to impaired secretion of gonadotropin-releasing hormone (GnRH).
(2) Hyperprolactinemia: prolactin increases in the body due to various causes, such as hypothalamic and pituitary disorders, certain endocrine disorders such as primary hypothyroidism, drugs such as estrogen, cimetidine can also cause an increase in blood prolactin, and some medical diseases such as hepatic steatosis, chronic renal failure, etc., or cause a decrease in hypothalamic prolactin-releasing inhibitory factor, or cause hyperprolactin secretion in the pituitary gland, and so on. This can lead to hyperprolactinemia, amenorrhea and infertility in women;
In men, prolactin affects the function of the hypothalamic-pituitary-testicular reproductive gonadal axis, and its effect involves almost all aspects of male reproduction, which can lead to delayed sexual development, decreased libido, erectile dysfunction, reduced semen, and even azoospermia. A few patients may also show lactation and breast development. Most of the pre-testicular lesions are treatable.
2, testicular causes
Testicular lesions are the main lesions that cause infertility, including: genetic lesions such as Crohn’s sign, Y chromosome microdeletion; congenital lesions such as cryptorchidism, infectious lesions such as orchitis; vascular lesions such as testicular torsion, varicocele, and immune and idiopathic lesions of unknown origin. Most of these disorders, except varicocele, do not have good treatment methods.
(1) Klinefelter’s syndrome
Klinefelter’s syndrone is the most common cause of clinical non-obstructive azoospermia, also known as congenital varicocele dysplasia, the incidence of which is about 0.2% of the male population, in 576 male live births, about 1 case, its typical clinical manifestations are small and hard testes, male mammary gland development and azoospermia. Kernicterus is a disease caused by chromosome number aberration, which is manifested by more than one X chromosome than normal, and its typical karyotype is 47,XXY.
(2) Cryptorchidism
Cryptorchidism or testicular descent insufficiency is a common cause of male infertility, which can be unilateral or bilateral. The cause of cryptorchidism is still not clear, but there are many factors that may cause incomplete testicular descent, because testicular descent is regulated by endocrine hormones, so endocrine abnormalities such as insufficient secretion of gonadotropins and testosterone may cause cryptorchidism, so patients with hypothalamic-pituitary disorders and patients with androgen synthesis disorders are prone to cryptorchidism, in addition to anatomical abnormalities and abdominal pressure drop (such as pear-shaped abdominal syndrome). In addition, anatomical abnormalities and decreased abdominal pressure (such as pear-shaped abdominal syndrome) can also be the cause of cryptorchidism.
Cryptorchidism accounts for about 8.5% of male infertility. This is due to the fact that the cryptorchid testis is in the inguinal region of the abdomen where the temperature is higher than the scrotum for a long time, which affects the normal development of the testis and produces a series of pathological changes. According to the data of a pathological examination of 78 cases of cryptorchid testes, 28% showed moderate hypofunction and 60% showed only supportive cell syndrome or spermatogenic arrest. The semen examination of patients may be azoospermia, oligospermia, oligozoospermia, etc.
In addition to infertility, the testicles of cryptorchidism are prone to cancer. According to some statistics, 28% of 599 cases of cryptorchidism patients have testicular tumor.
(3) Varicocele
The incidence of varicocele is 10-15% in young adults and up to 40% in infertile men. 80-98% of varicocele occurs on the left side, 20% on both sides, and only 2% on the right side.
The cause of varicocele in male infertility is still not very clear, and may be related to the following factors: due to blood reflux and stagnation, the temperature of the scrotum rises, causing atrophy of the testicular varicocele, affecting the production of sperm, followed by toxic substances and blood retention, causing changes in testicular hemodynamics, causing testicular ischemia and hypoxia, and also interfering with the endocrine function of the testicular mesenchymal cells, these adverse effects, also spill over These adverse effects also affect the epididymis, making the function of the epididymis also decreased, because the left side and the right side of the spermatic cord tracheal plexus have abundant traffic branches, so the lesion on one side will also affect the opposite side, and make the bilateral testes epididymis damaged at the same time.
On physical examination, the patient’s scrotum can be seen to be sagging on the sick side and the varicose veins can be palpated in the shape of earthworm masses, which will disappear or shrink when lying down. The diagnosis of varicocele is easy, but it should be noted that only varicocele with semen abnormalities can be considered as the cause of infertility.
Second, the diagnosis of male infertility
1, medical history taking
As with other clinical diseases, history taking plays a very important role in the diagnosis of infertility and should be given due attention as it is not replaced by other methods. In estimating the duration of infertility, attention should be paid to the exclusion of contraceptive time. The patient’s marital history and sexual history should be questioned not only in detail, but also in a manner that pays attention. Pay attention to the impact of environmental factors on the patient such as high temperature, radiation exposure and poor lifestyle habits such as alcoholism and smoking. Past histories such as mumps, cryptorchidism and hernia surgery should also be noted. In order to avoid the omission of medical history, it is useful to make an outline of medical history taking and medical record format by referring to relevant information.
2.Physical examination
First of all, we should pay attention to the patient’s general condition, nutrition, body shape, secondary sexual characteristics and external genital development, whether there are signs of hypogonadism, whether there is hyposmia or absence of smell, the examination of the reproductive system, especially should pay attention to the patient’s vulva, scrotum, testes, epididymis, prostate, seminal vesicles.
The testicular volume is an important indicator, to a certain extent, can reflect the function of the testicles, at present, the testicular volume measurement meter is mostly used to measure the testicular volume, our scholars have determined that the average volume of normal male testicles is 19.8 ± 3.3 ml, if the testicle is less than 11 ml is abnormal, in addition, the testicular hardness estimation is also very important, because in the testicular volume hardness examination, easily affected by the thickness of the scrotum and indoor The testicular volume and stiffness are also important because they are affected by the thickness of the scrotum and the temperature of the room, so the examiner needs to be careful and experienced.
In addition, the examination of epididymis, vas deferens, scrotum and seminal vesicles of prostate is also very important, for example, congenital malformation of vas deferens – vas deferens is mostly found through physical examination.
3.Laboratory examination
(1) semen routine examination: semen examination is the most important and practical test to estimate male fertility, among dozens of laboratory tests related to reproduction, there is no doubt that the semen routine examination is the most important, it is the diagnosis of male infertility, to determine the quality of a sperm donor’s semen to determine the main test items, in most scientific studies on reproduction and family planning, mostly semen parameters, as a gold standard, analysis of experimental In most scientific studies on reproduction and family planning, semen parameters are used as a gold standard to analyze the results of experiments and to explore their correlation.
However, routine semen examination has certain limitations and sometimes cannot make a correct and objective judgment on male fertility, and there are large errors in the test.
(2) Reproductive endocrine hormone measurement: mainly detects the level of hormones such as FSH (oxytocin), LH (luteinizing hormone), T (testosterone), PRL (prolactin), etc., which can be used to understand the functional status of the hypothalamic-pituitary-testicular gonadal axis system, which is of certain value for clinical diagnosis. For example, a decrease in FSH and LH is considered hypogonadotropic hypogonadism, indicating that the lesion is in the hypothalamus or pituitary gland.
If FSH and LH are elevated, it is hypogonadotropic hypogonadism, which indicates that the lesion is in the testes. If PRL is elevated, it is a sign of hyperprolactinemia, and the lesion is in the pituitary gland, such as pituitary tumors. Since FSH, LH and PRL hormones are secreted in a pulsatile manner, they should be measured several times or twice with an interval of 15-20 minutes to ensure the accuracy of the results.
4.Special examination
(1) vas deferens, seminal vesiculography: vas deferens seminal vesiculography is a damaging examination, which can not only bring pain to the patient, but also inadvertent operation during the examination can even cause vas deferens obstruction, so the indications should be strictly selected.
(2) Testicular biopsy: In addition to semen analysis, testicular biopsy is probably the most important test for male infertility. Through testicular biopsy, it is possible to understand the pathological changes in the testis, the status of spermatogenesis, clarify the site of the lesion, perform quantitative histological analysis, and assess the prognosis.
(3) B-type ultrasound and Doppler examination: it has very important use and value in the examination and diagnosis of the male genital system, and can be used for the examination of varicocele, scrotal content, prostatic seminal vesicles, and the diagnosis of obstructive azoospermia, etc. Ultrasound examination is non-invasive, simple, convenient and reproducible, and provides important information for diagnosis, and is relatively inexpensive.