People tend to focus only on the role played by the woman in the conception of the little one because the entire process from the fertilization of the egg to the birth of the child is done in the mother’s womb. However, the role of the father-to-be should not be overlooked. The quality of semen, especially the sperm contained therein, is equally important in the conception of offspring. Sperm are male reproductive cells that look a bit like tadpoles. In males, the testes produce sperm continuously from puberty onwards, followed by further development and maturation in the epididymis where they are stored. During sexual intercourse, sperm enter the vas deferens and seminal vesicle glands and, together with prostate fluid, are expelled from the erect penis through ejaculation. Only if normal sperm is discharged into the vagina of the mother-to-be at the right time (the woman’s ovulation period) will the egg be fertilized. So, how can we know if the father-to-be’s sperm is normal? It’s easy, just do a semen test. Composition of Semen Semen is a grayish or yellowish liquid made up of products of the testes, epididymis, seminal vesicles and prostate, and also contains a small amount of secretions from the urethral glands. Sperm is the component we are most concerned about and is the most important formative component of semen, accounting for about 5 to 10%. The rest of the liquid component is called seminal plasma, which is the medium necessary for the transportation of spermatozoa, of which the seminal vesicle secretion accounts for 60% to 70%, and the prostatic fluid accounts for 20% to 30%. Collection of semen specimen Semen examination first requires the subject to collect his own semen, whether the correct collection of semen specimen can affect the accuracy of the test results. Men should abstain from sex for 3 to 5 days before semen collection, if the time is too short or too long, it will affect the test results. Using masturbation or intercourse in vitro ejaculation, all semen should be collected in a clean container and kept in an environment close to body temperature (e.g., under close-fitting underwear) to be sent to the laboratory for examination as soon as possible. Condoms should not be used because the condoms normally used contain spermicidal substances that can cause sperm to die. Routine semen examination Routine examination is the most important part of semen examination, which generally includes semen color, semen volume, liquefaction time, sperm density, 1-hour survival rate, sperm vitality, percentage of malformed sperm, white blood cell count, and so on. (1) Semen color: the color of normal semen is transparent off-white, if abstinence for a long time, it can be light yellow, yellow or even pink when there is inflammation in the reproductive tract. (2) Semen volume: the general amount of semen per discharge is 2ml to 5ml, but affected by the frequency of semen discharge and the number of times. (3) Semen liquefaction time: semen is gel when it is first discharged from the body, and it will become liquid after 5 to 30 minutes, a process called liquefaction. The liquefaction of semen requires the participation of a series of protein hydrolyzing enzymes. Thick and non-liquefied semen is common in patients with prostate or seminal vesicle diseases. (4) Sperm density: Sperm density refers to the number of spermatozoa contained in each milliliter of semen, and the number of spermatozoa in each milliliter of normal semen is more than 20 million. (5) 1-hour sperm survival rate: the percentage of active spermatozoa should be ≥60% within 1 hour after sperm discharge. (6) Sperm vitality: there are four grades, A, B, C and D, which represent the spermatozoa making fast straight forward movement, slow forward movement, swinging in place and inactivity respectively. Normal spermatozoa viability grade A ≥ 25% or grade A+B ≥ 50%. (7) Percentage of malformed sperm: malformed sperm refers to sperm with abnormal morphology, and its percentage should be below 30%. (8) Number of leukocytes in semen: the number of leukocytes in each high magnification field of view should be less than 5 under normal conditions. If it is more than 5, there may be inflammation of the reproductive tract. Bacteriologic examination of semen: When abnormalities are found in routine semen examination, it is better to do another bacteriologic examination of semen. Infections in the male reproductive system, such as the presence of staphylococcus, E. coli, enterococci, mycoplasma, chlamydia and other pathogenic microorganisms, can cause changes in semen quality. Semen biochemistry test: If possible, the content of fructose, zinc, acid phosphatase and carnitine in semen can also be detected. Fructose is mainly secreted by the seminal vesicle glands, providing the energy needed for sperm activity. The absence or reduced content of fructose is seen in congenital seminal vesicle deficiency and seminal vesiculitis, etc. Fructose is not easy to conceive when it is insufficient. The prostate gland contains a high concentration of zinc and acid phosphatase, and the epididymis contains a high concentration of carnitine, which are related to the function of the spermatozoa. When inflammation occurs in the prostate gland and epididymis, the content of these substances will be reduced, thus affecting fertility.