Semen is the milky fluid that a man’s penis releases during orgasm. Semen consists of fluid and sperm. The fluid comes from the prostate gland, seminal vesicle and other sex glands. The sperm is produced in the testicles. During orgasm a man ejaculates (releases semen through the penis). The seminal fluid helps transport the sperm during ejaculation. The seminal fluid has sugar in it – sugar is an energy source for sperm.
Abnormal semen is responsible for about 75% of all cases of male infertility. Unfortunately, in many cases doctors never find out why. The following semen problems are possible:
• Low sperm count (low concentration) – the man ejaculates a lower number of sperm, compared to other men. Sperm concentration should be 20 million sperm per milliliter of semen. If the count is under 10 million there is a low sperm concentration (subfertility).
• No sperm – when the man ejaculates there is no sperm in the semen.
• Low sperm mobility (motility) – the sperm cannot “swim” as well as it should.
• Abnormal sperm – perhaps the sperm has an unusual shape, making it more difficult to move and fertilize an egg.
Sperm must be the right shape and able to travel rapidly and accurately towards the egg. If the sperm’s morphology (structure) and motility (movement) are wrong it is less likely to be able to reach the egg and fertilize it.
The following may cause semen to be abnormal:
• Testicular infection
• Testicular cancer
• Testicular surgery
• Overheating the testicles – frequent saunas, hot tubs, very hot baths, or working in extremely hot environments can raise the temperature of the testicles. Tight clothing may have the same effect on some people.
• Ejaculation disorders – for some men it may be difficult to ejaculate properly.
Men with retrograde ejaculation ejaculate semen into the bladder. If the ejaculatory ducts are blocked or obstructed the man may have a problem ejaculating appropriately.
• Varicocele – this is a varicose vein in the scrotum that may cause the sperm to overheat.
• Undescended testicle – one (or both) testicle fails to descend from the abdomen into the scrotum during fetal development. Sperm production is affected because the testicle is not in the scrotum and is at a higher temperature. Healthy sperm need to exist in a slightly lower-than-body temperature. That is why they are in the scrotum, and not inside the body.
• Hypogonadism – testosterone deficiency can result in a disorder of the testicles.
• Genetic abnormality – a man should have an X and Y chromosome. If he has two X chromosomes and one Y chromosome (Klinefelter’s syndrome) there will be an abnormal development of the testicles, low testosterone, and a low sperm count (sometimes no sperm at all).
• Mumps – this viral infection usually affects young children. However, if it occurs after puberty inflammation of the testicles may affect sperm production.
• Hypospadias – the urethral opening is at the underside of the penis, instead of its tip. This abnormality is usually surgically corrected when the male is a baby. If it is not the sperm may find it harder to get to the female’s cervix. Hypospadias occur in about 1 in every 500 newborn boys.
• Cystic fibrosis – Cystic fibrosis is a chronic disease that affects organs such as the liver, lungs, pancreas, and intestines. It disrupts the body’s salt balance, leaving too little salt and water on the outside of cells and causing the thin layer of mucus that usually keeps the lungs free of germs to become thick and sticky. This mucus is difficult to cough out, and it clogs the lungs and airways, leading to infections and damaged lungs. Males with cystic fibrosis commonly have a missing or obstructed vas deferens (tube connecting the testes to the urethra; it carries sperm from the epididymis to the ejaculatory duct and the urethra).
• Radiotherapy – radiation therapy can impair sperm production. The severity usually depends on how near to the testicles the radiation was aimed.
• Some diseases – the following diseases and conditions are sometimes linked to lower fertility in males:
Sulfasalazine – this anti-inflammatory drug can significantly lower a man’s sperm count. The drug is often prescribed for patients with Crohn’s disease or rheumatoid arthritis. Usually this side effect goes away after the patient stops taking the medication.
Anabolic steroids – often taken by bodybuilders and athletes; anabolic steroids, especially after long term use can seriously reduce sperm count and mobility.
• Chemotherapy – some medicines may significantly reduce sperm count.
• Illegal drugs – consumption of marijuana and cocaine can lower a man’s sperm count.