Male infertility and its management by Prof. Oladapo Ashiru
Infertility is defined as the inability to achieve pregnancy after one year of unprotected sexual intercourse. The American Society for Reproductive Medicine, the African Fertility Society and other fertility organisations, in a recent meeting of WHO experts, revised the definition of infertility to encourage earlier evaluation in the highest risk groups.
According to the new guideline 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. Even more, 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, with approximately 35 per cent of the cases due to female factors alone, 30 per cent due to male factors alone and 20 per cent due to a combination of female and male factors.
While 15 per cent of the cases are regarded as unexplained infertility, the conditions of the male that affect fertility, also 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 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 to placental and embryonic development. Genetic and epigenetic alterations of the sperm may, therefore, have 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 the 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 the 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. Still, more than 50 per cent of cases of male infertility 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 relation 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 evaluations. The couple should be explicitly asked 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 a 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 the 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 are ejaculated out of the penis. 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 to achieve the goal of fertilisation. A “normal” sperm count is about 20 million or more sperm per millilitre of semen. Over 60 percent 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 all affect male fertility.
To be continued