Male infertility: Current concepts, causes and management
The conditions affecting male fertility, which are responsible for a whopping 30 per cent of infertility cases, are still generally under-diagnosed and undertreated.
A man’s fertility generally relies on the quantity and quality of his sperm. If the number of sperm that a man ejaculates is low or if the sperm is of poor quality, it will be difficult and sometimes impossible for him to achieve pregnancy.
Male infertility is usually caused by problems that affect either sperm production in the testes or sperm transport. The male gamete contributes 50 per cent of the genomic material to the embryo and placental and embryonic development. Genetic and epigenetic alterations of the sperm, therefore, may have Infertility is defined as the inability to achieve pregnancy after one year of unprotected intercourse (WHO -ICMART glossary). Recently, the American Society for Reproductive Medicine, the African Fertility Society and other fertility organisations, at a WHO expert meeting, revised the definition of infertility to encourage earlier evaluation in the highest risk groups.
According to the new guidelines to be published by a consortium of fertility groups, women and men over 35 years of age are now encouraged to seek fertility evaluation, if they fail to conceive after only six months of trying. More so, studies continue to make additional exposures on male infertility.
An estimated 15 per cent of couples meet this criterion and they are considered to be infertile. Approximately 35 per cent of all infertility cases are due to female factors alone. About 30 per cent are due to male factors alone and 20 per cent due to a combination of female and male factors, just as 15 per cent are regarded as unexplained infertility.
significant consequences on early pregnancy.
Epigenetic alterations in the sperm, such as altered chromatin packing, imprinting errors, absence or modification of the centrosome, telomeric shortening, and lack of sperm RNA, can affect some of the functional characteristics of conception, leading to early embryo loss. It is now noteworthy to realise that recurrent pregnancy loss in a woman may be due to abnormalities in her man’s semen.
Recurrent pregnancy loss, defined as the miscarriage of two or more consecutive pregnancies in the first or early second trimester of gestation, may be associated with endocrine, anatomical, psychological, infectious, thrombotic, genetic, or immunological causes. More than 50 of cases remain unexplained by these known causes, even after extensive evaluation.
In reality, the frequency with which sperm defects contribute to recurrent pregnancy loss has not been fully established and the relationship between standard semen parameters and recurrent miscarriage has been a controversial subject. Male partners among couples with recurrent pregnancy loss show a significant increase in sperm chromosome aneuploidy, abnormal chromatin condensation, DNA fragmentation, increased apoptosis, and abnormal sperm morphology, compared with other men.
The initial step in the evaluation of an infertile male is to obtain a thorough medical and urologic history. Important considerations include the duration of infertility, previous fertility in the patient and the partner, and prior evaluation. The couple should be asked explicitly about their sexual habits, including their level of knowledge of the optimal timing of intercourse and the use of potentially spermicidal lubricants.
Male patients should be asked about their history of childhood illnesses, such as testicular torsion, post-pubertal mumps, developmental delay, precocious puberty, urinary tract infections, sexually transmitted diseases and bladder neck surgery.
Also crucial for consideration is a history of neurological disorders, diabetes and pulmonary infections. Anosmia (lack of smell), galactorrhea, visual-field defects and sudden loss of libido could be signs of a pituitary tumour.
The production of sperm is a complex process and it requires normal functioning of the testicles (testes), as well as the hypothalamus and pituitary glands – organs in your brain that produce hormones that trigger sperm production. Once the sperm is produced in the testicles, delicate tubes transport them until they mix with other components of semen and ejaculated. Problems with any of these processes can affect sperm production.
Low sperm count (oligospermia) is a leading cause of infertility or sub-fertility issues among men. While it requires only one sperm to fertilise the ovum, the odds of conception are such that it takes millions of sperm per millilitre of semen actually to achieve the goal of fertilisation.
A “normal” sperm count is about 20 million or more sperm per millilitre of semen. Over 60 per cent of the sperm in each sample should exhibit normal morphology and indicate normal motility – the forward swimming movement. Oligospermia can be easily diagnosed with simple tests that reveal the concentration of sperm in a given sample quantity.
Diet, the frequency of intercourse and general health and wellness issues affect male fertility. Other factors commonly implicated include:
Drug use: Anabolic steroids taken to stimulate muscle strength and growth can cause the testicles to shrink and sperm production to decrease. Use of cocaine or marijuana might reduce the number and quality of your sperm as well.
Alcohol use: Drinking alcohol, especially in excess, can lower testosterone levels and cause decreased sperm production.
Occupation: Certain occupations pose a risk of infertility. Recent studies have shown a clear link between specific environmental toxin exposure and infertility.
Tobacco smoking: Men who smoke might have a lower sperm count than do those who do not smoke.
Weight/ Obesity can impair fertility in several ways, including directly affecting sperm and by causing hormone changes.
Known causes of male infertility
Sperm production problems
Chromosomal or genetic causes
- Undescended testis or twisting of testes in scrotum (tortion)
- Medicine and chemicals
- Damage caused by radiation
- Unknown causes
- Blockage of sperm transport
- Absence of Vas Deferens
- Sexual problems (Erection and ejaculation dysfunctions
- Failure of ejaculation
- Erectile dysfunction
- Infrequent intercourse
- Spinal cord injury
- Prostate diseases and surgery
- Retrogade and premature ejaculation
- Hormonal problems
- Anabolic steroid use
- Pituitary tumours
- Sperm antibodies
- Infection in the epididymis
In general, scientists and fertility doctors are noticing a drop in sperm count and motility, which makes it harder for couples to make babies. Other factors attributed to this include:
Plastics: Bisphenol A, an additive to plastics found in many household products can lower sperm count and motility. A 2008 study in the journal Fertility and Sterility showed that men with high concentrations of BPA in their urine also had low sperm counts. Food packaging is a significant source of BPA, which can seep into foods.
Pesticides: Scientists have also noted that farmers living in rural areas are exposed to pesticides used on the farm and they tend to have a low sperm count. The chemical run-off from pesticides can get into tap water and disrupt hormonal processes.
Tumours: Cancers and non-malignant tumours can affect the male reproductive organs directly through the glands that release hormones related to reproduction, such as the pituitary gland, or through unknown causes. Surgery, radiation or chemotherapy used in the management of tumour can also affect male fertility.
Undescended testicles: During fetal development, one or both testicles sometimes fail to descend from the abdomen into the sac that usually contains the testicles (scrotum). If left uncorrected, this can cause decreased fertility when the child grows, as the undescended testes are unable to produce healthy sperms necessary for conception.
To be continued…