CAUSES OF INFERTILITY
Infertility is defined as the inability to
conceive after a year of unprotected sexual intercourse. Non-endocrine causes
refers to those causes not related to secretion of hormones by glands directly
into blood. Causes of infertility can be due to female factors alone, male
factors alone or a combination of both. Approximately 30-40% of infertility cases
are as a result of a male factor, while the female factor contributes 40-50%. The
remaining 10-30% of infertility cases may be due to contributing factors from
both of the partners or unexplainable cause.
It is one of the most common causes of
female sterility. The condition
is characterised by growth of endometrial tissue, almost similar to that of
normal uterine endometrium, in the pelvic cavity. It may grow around the
uterus, fallopian tubes, or ovaries.
Endometriosis leads to fibrosis throughout the pelvis. This fibrosis sometimes
surrounds the ovaries that an ovum cannot be released into the abdominal
cavity. Often, it may also occlude the fallopian tubes, either at the ends or
somewhere else along their extent.
Danazol is used to treat endometriosis, it is an androgen similar to testosterone. For
the treatment of endometriosis, it works by decreasing the amount of hormones made by the ovaries.
Salpingitis is inflammation of the oviducts. This
condition results in fibrosis in the tubes, thereby occluding them. Such
inflammation occurs mainly due to infection. Different conditions that give rise to infections
Transmitted Diseases such as, Chlamydia trachomatis and gonorrhea
Salpingitis is treated with antibiotics in order to fight the
Obesity is characterized by hyperleptinemia. The
effects of obesity on the female reproductive health is due to the cumulative
effects of leptin in the ovary and brain.
There is some evidence that weight reduction
(including through bariatric surgery in the obese) can help reverse this.
Fibroid tumors that are benign in the uterus are mostly common in women
during their thirties. However, large fibroids may lead to infertility by
impairing the uterine lining, occluding the oviduct, or by destroying the shape
of the uterine cavity or changing the cervix’s position
Medications given for treatment of uterine fibroids target the hormones
that regulate the menstrual cycle. They treat symptoms such as pelvic pressure and
heavy menstrual bleeding. They do not eliminate fibroids, but may decrease
their size by shrinking them.
It is otherwise known as uterine synechiae. This condition is
characterized by formation of intrauterine adhesions and scarring inside the
uterus, which can lead to occlusions and secondary amenorrhea. May result from repeated
injury, surgery, or unknown factors. During treatment the goal of is to remove
the adhesions and ultimately restore the normal size and shape of the uterine
cavity. This is commonly done by lysis of the adhesions via hysteroscopy. The
resultant outcome correlates with the extent of uterine cavity occlusion and
type of adhesions.
This condition is caused by twisting
of the spermatic cord, leading to a loss of blood flow to the testicle. It may
lead to loss of the affected testicle unless treated promptly.
The cause of most cases is the
bell clapper deformity. This is an anatomic abnormality present in some males
that allows the spermatic cord to twist more easily, which may be associated
with trauma or can occur spontaneously.
Surgery is the recommended
treatment for testicular torsion, although on rare occasions, a physician may
be capable of manually untwisting the testicle.
It also known as germ cell
aplasia, and it describes a condition of the testes in which only Sertoli cells
line the seminiferous tubules. Sertoli cells help to make up the blood-testis
barrier and are responsible assisting with sperm production
This condition is characterized
by azoospermic semen due to the inability to produce sperm. The cause of
Sertoli-cell-only syndrome is not exactly known. However, some researchers believe the condition
develops from irradiation, hormonal therapy, environmental toxins, gonadotropin
deficiencies, and other factors.
Those diagnosed with germ cell
aplasia can only be treated by donor or de novo generated gametes.
Spermatogenesis arrest is a process
of interruption in the differentiation of germinal cells of specific cellular
type that elicits an altered spermatozoa formation. It is usually caused by genetic factors
resulting in irreversible azoospermia. However some cases may be consecutive to
thermic, hormonal or toxic factors and may be reversible either after a
specific treatment or spontaneously.
FSH treatment can increase the spermatogonial population in oligozoospermic
men with normal hormonal profiles and improve sperm production quantitatively
Radiation therapy is used in cancer treatment. It can stop or slow down sperm cell production if the testicle is in or near
the target area for the radiation. To help protect the testicles a lead shield
can be used, but radiation scatters within the body, thus not possible to
shield the testicles completely.
This is infertility in which the cause remains
unknown even after an infertility work-up. A study was done and it was found that there are three recurrent deletions of X
chromosome linked copy number variations (CNVs), CNV64, CNV67 and CNV69 associated with idiopathic male infertility in
Italian and Spanish populations, especially CNV67 resembling the azoospermia
Ma, X., Hayes, E., Prizant, H., Srivastava, R. K., Hammes, S. R., &
Sen, A. (2016). Leptin-induced CART (cocaine-and amphetamine-regulated
transcript) is a novel intraovarian mediator of obesity-related infertility in
females. Endocrinology, 157(3), 1248-1257.
Bridges, P. J., Jeoung, M., Shim, S., Park, J. Y., Lee, J. E.,
Sapsford, L. A., … & Jo, M. (2012). Hematopoetic prostaglandin D synthase:
an ESR1-dependent oviductal epithelial cell synthase. Endocrinology, 153(4),
Hellstrom, W. J. (Ed.). (2012). Male
infertility and sexual dysfunction. Springer Science & Business
Hall, J. E., Guyton,
A. C. (2010). Guyton and Hall Textbook of Medical Physiology. 12th
Edition. Saunders, Philadelphia, USA