Male Fertility
Understanding fertility in men
Conceiving a healthy baby depends on a number of factors, including healthy sperm. In fact, male infertility is the second biggest issue after a woman’s age so it’s important to understand how the male reproductive system works.
Male factor infertility affects around half of all infertile couples, the good news is that the most common causes of male infertility are easily diagnosed, and most can also be treated.
Producing sperm
Sperm production starts in the testes, where the hormone testosterone is also produced. An average of 100 million sperm are produced every day in healthy young men. After sperm is produced, it will need to travel along a long channel system starting at the epididymis, where they mature along the way, before exiting via the ductal structures called vas deferens and then out the urethra as part of the ejaculate. The entire process of sperm production and maturation takes just under 3 months. Any serious illness may affect sperm production for up to three months.
A sperm consists of the head, tail and mid-piece sections. To successfully fertilise an egg, the sperm will need to be able to move its tail (motility) to propel itself through cervical mucus to then travel through the uterus and fallopian tube to reach the egg. It will also need to be normally shaped in order to penetrate the outer shell of the egg to deliver its genetic package contained in the head.
There are four key components necessary to achieve satisfactory sperm production and a pregnancy:
- Normal hormonal stimulation from the pituitary gland
- Normal sperm production in the tubules of the testes
- An unobstructed sperm pathway
- Effective natural sperm delivery
Try our Male Fertility Predictor.
Male Infertility: cases, treatments & symptoms
Problems with sperm production
The most common causes of male infertility are called:
- Azoospermia, no sperm cells are produced
- Oligospermia, where few sperm cells are produced
- Teratospermia, where a high proportion of sperm is abnormally shaped
- Blocked or absent vas deferens:
- Vas deferens is the tube that transports the sperm from the testes
- Genetic condition such as cystic fibrosis or chromosomal abnormality
- High sperm DNA fragmentation that can affect a sperms ability to fertilise an egg
- Sperm antibodies that can interfere with sperm motility and fertilisation
It’s usually a good sign if you have ever conceived a baby with any partner in the past, but this may not mean that your sperm is compatible with your current partner.
Sperm production
Healthy sperm is vital to conceive a baby, which is made up of the head, where the genetic material needed for fertilisation is stored, a neck (mid-piece) and a tail for propulsion towards the egg.
More than 15 million sperm per mL need to be present in the semen for natural conception, and more than half of these need to be able to move forward quickly, with at least 4% bearing a normal shape.
Sperm and testosterone are both produced in the testes. Sperm then passes slowly through a series of long coiled tubules called the epididymis, where they mature so they can swim and penetrate an egg cell. They then travel via the vas deferens to the urethra and out of the penis as they are ejaculated.
The entire process of sperm formation takes about 72 days. Serious illness during this time can affect sperm quality and production for up to three months.
Abnormal sperm production
The most common causes of male infertility are:
- Azoospermia - where no spermatozoa are produced and/or found in the ejaculate.
- Oligospermia – where fewer spermatozoa are produced.
Sometimes, spermatozoa are malformed, and in rare cases, genetic diseases may be at fault. Other specific conditions include:
- Immunological infertility – where you develop antibodies against your own sperm
- Retrograde ejaculation – where sperm are not ejaculated through the urethra but into the urinary bladder
- Blockages in the vas deferens, due to injury or a previous vasectomy
- Subnormal quality of sperm
It is good to know that we have treatment strategies for all forms of male infertility – so if you are diagnosed with any of these symptoms, or a combination of both male and female causes, Virtus Fertility Centre Singapore can help.
How Does Age Affect Fertility in Men?
Men produce sperm their whole lives, so the effect of age on a man’s fertility is not as dramatic as in women. However, there are some important lifestyle factors to take into consideration. Sperm quality can be affected by:
- Smoking
- Excessive alcohol
- Prescription medication, steroids and other drug use
- Excess weight and high Body Mass Index (BMI)
- Frequent exposure to heat
- Working in cramped conditions
- Exposure to environmental pollutants (e.g. bisphenol A found in plastic containers, pesticides etc)
- Exposure to radiation
- Acute viral illness
What affects sperm quality?
- Health & lifestyle factors such as smoking, excessive drinking, drugs including steroids and recreational use, and weight and Body Mass Index
- Past medical conditions such as an undescended testes, hernia, STD or severe trauma.
- Acute viral illness can also temporarily affect sperm health.
There is no scientific evidence that wearing tight clothes or bike shorts affects the quality of your sperm. Diet, vitamins and supplements actually have very little impact on your sperm count - but they do help you stay healthy.
Sports injuries to the groin will only have an impact on sperm production in extremely severe cases.
While the effect of age on a man's fertility is not as significant as it is with women, there is a decline in the quality of sperm after the age of 45. After this age, sperm volume, motility and morphology declines and damage to sperm DNA increases.
Other causes of male infertility
Retrograde ejaculation
Retrograde ejaculation is a condition in which some or all semen flows backwards into the bladder rather than out through the urethra during ejaculation. Symptoms include producing little or no semen during ejaculation and can be diagnosed with a urine sample and semen analysis. If you are trying to conceive, retrograde ejaculation can be treated using assisted reproductive technology such as intrauterine insemination, IVF or ICSI procedures. Sperm can be collected from the urine or surgically retrieved from the testis. A fertility specialist can explain your options and help you choose the best path for you.
Immunological infertility
Male immunological infertility occurs when a man develops antibodies against his own sperm. These anti-sperm antibodies attach to the sperm affecting the way they move and their ability to penetrate a woman’s cervical mucus and fertilise the egg. The presence of anti-sperm antibodies is commonly the result of vasectomy, injury or injection but it does not mean a man won’t be able to conceive a child. Intracytoplasmic Sperm Injection (ICSI) can be used to help achieve a pregnancy.
Hyperprolactinemia
Hyperprolactinemia refers to elevated levels of the prolactin hormone in the blood stream. In men this can cause infertility by affecting the function of the testicles, decreased testosterone levels, decreased sex drive and abnormal sperm production. If hyperprolactinemia is affecting your fertility there are treatments available and your fertility specialist will guide you on the one most appropriate for you.
Occlusion
Occulsion refers to a blockage in a man’s reproductive system, often in the epididymis or vas deferens, which prevents sperm reaching the urethra. Occlusions in men could be a result of injury, vasectomy or a congenital condition. It can be treated using a Vasovasectomy which is a surgical procedure which reconnects the ends of the vas deferens together or a testicular biopsy to surgically retrieve sperm from the testis for use in IVF or ICSI treatment.
Male fertility tests
A semen analysis is the most important test male fertility test.
If a male has had repeated abnormal semen analysis a specialist may suggest a sperm DNA fragmentation test.
Treatment for male infertility
There are not many treatments that will improve the quality of the sperm themselves. However there are a number of treatments available to help a couple make the best of sperm quality as it is, and achieve a pregnancy include:
- Lifestyle changes
- Simple drug treatments such as Gonadotrophin to improve sperm numbers
- Intrauterine insemination if sperm abnormalities are not too severe
- In-vitro fertilisation with Intra-cytoplasmic Sperm Injection (ICSI) for severe sperm abnormalities which involves injecting a single sperm into each egg to achieve fertilisation
- Micro-epididymal sperm aspiration or (MESA) to surgically retrieve sperm from the epididymis if there are no sperm in the ejaculate or from the testes themselves with Testicular Sperm Aspiration (TESA)
- Digital high magnification for high level of DNA fragmentation to view and select the healthiest sperm
- Donor insemination in the most severe cases
