Why do sterility problems exist?

Sterility and fertility

What are the causes of female sterility?

There are various factors which cause infertility or sterility in women. Most are irreversible, but those involving anatomical alterations can be solved with surgical intervention. It is becoming more and more accepted that the quality of the egg is of critical importance and this is closely linked to the age of the woman. Women of advanced age have eggs with a reduced capacity for fertilization:

Ovarian factors: This includes all those cases where ovulation does not occur. This is usually due to hormonal problems, either the lack of hormones or the excess of some of the regulators of endocrine function: ovarian polycystic syndrome (OPS), anovulation, ovarian failure or premature menopause.

Uterine factors: In this case, it is much more usual for infertility and not sterility to be caused. Fundamentally it involves alterations to the internal anatomy of the uterus which may be congenital or acquired and can provoke repeated miscarriages: uterine deformities (partial or total duplication of the uterus, septums); acquired causes (polyps; myomas; synechia; endometritis).

Tubaric factors: This includes all those anomalies of the Fallopian tubes which impede the meeting of the egg with the sperm: absence, impermeability or obstruction of the tubes; salpingitis.

Cervical factors: In this case, the cause comes from anatomical and/or functional alterations of the neck of the uterus which interfere with the correct migration of the sperm towards the uterus and the Fallopian tubes in their attempt to find the eggs: impermeability of the neck of the uterus (polyps, cysts), past surgery (conisation).

Genetic factors: Chromosome anomalies which cause miscarriages.

 

What are the causes of male sterility?

Some of the factors affecting male sterility are:

Genetic factors: Most of these are associated with sperm anomalies, either directly or indirectly: cystic fibrosis, karyotype anomalies like Klinefelter’s syndrome, translocations,…

In most cases of male infertility and low quality sperm, there are no clear causes that can be identified using the diagnostic methods currently available. There is some speculation that mutations of the Y chromosome could be an important factor.

Anatomical factors: Obstructions in the ducts the sperm passes through can cause sterility as they partially or totally block the exit of the seminal liquid. Some of these anomalies can be of congenital origin (present at birth) or acquired (infections, scars from surgery on the urogenital tract).

Environmental factors: Lifestyle can reduce the quantity and quality of the sperm (tobacco, alcohol, and other drugs).

Other types of illnesses: There are illnesses that can appear after birth and that can influence male sterility: infection with the parotiditis virus (mumps), hormonal dysfunction…

 

What is combined sterility?

In some cases, both the man and the woman can be sterile and the couple’s difficulty in conceiving is a result of a combination of these conditions. In other cases, in which the cause could be immunological or genetic, it is possible that both people can be independently fertile but the couple together cannot conceive without assistance.

 

Does sterility of unknown origin exist?

In around 10% of cases, the basic sterility study does not show any anomalies. In these cases, the abnormalities are probably present but cannot be detected using the methods currently available.

 

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