Published February 13, 2019
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