Infertility
is “a disease of the reproductive system defined by the failure to achieve a
clinical pregnancy after 12 months or more of regular unprotected sexual
intercourse (and there is no other reason, such as breastfeeding or
postpartum amenorrhoea). Primary infertility is infertility in a couple who have
never had a child. Secondary infertility is failure to conceive following a
previous pregnancy. Infertility may be caused by infection in the man or
woman, but often there is no obvious underlying cause.
Primary vs. secondary infertility
Primary infertility is the absence of a live birth for women who desire a child
and have been in a union for at least five years, during which they have not
used any contraceptives.
The World Health Organization also adds that
'women whose pregnancy spontaneously miscarries, or whose pregnancy results
in a still born child, without ever having had a live birth would present
with primarily infertility'
While Secondary
infertility is defined as the
absence of a live birth for women who desire a child and have been waiting
for at least five years since their last live birth, during which they did
not use any contraceptives.
Effect of infertility:
Infertility may have profound psychological
effects.
Like - Partners becoming more anxious to
conceive, leading to increase in sexual dysfunction.
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Marital discord which often develops in infertile couples,
especially when they are under pressure to make medical decisions.
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Women trying to conceive often have clinical depression rates
similar to women who have heart disease or cancer.
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Even couples undertaking IVF face considerable stress.
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The emotional losses created by infertility include the denial
of motherhood as a rite of passage;
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The loss of one’s anticipated and imagined life;
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Feeling a loss of control over one’s life;
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Doubting one’s womanhood;
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Changed and sometimes lost friendships;
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And, for many, the loss of one’s religious environment as a
result of searching for solution, or support system.
Meanwhile, the emotional stress and marital
difficulties are greater in couples where the infertility lies with the man.
Sexually transmitted disease
Infections with the following sexually
transmitted pathogens have a negative effect on fertility:
Infection and female reproductive tract
syndromes.
Other causes,
Factors that can cause male as well as
female infertility are:
DNA damage
DNA damage reduces fertility in female ovocytes, as caused by
smoking, other xenobiotic DNA damaging agents (such as radiation or
chemotherapy) or accumulation of the oxidative DNA damage
8-hydroxy-deoxyguanosine
DNA damage reduces fertility in male sperm, as caused by
oxidative DNA damage, smoking, other xenobiotic DNA damaging agents
(such as drugs or chemotherapy) or other DNA damaging agents including
reactive oxygen species, fever or high testicular temperature.
General factors:
Hypothalamic-pituitary factors
Hyperprolactinemia-- if prolactin levels are high and the woman is not pregnant or
breastfeeding, it may affect ovulation and fertility.
Environmental
factors
Tobacco smokers are 60% more likely to be infertile
than non-smokers. - smoking significantly increases the risk
of infertility in both men and women. Smoking may also undermine the effects
of fertility treatment. Even when a woman gets pregnant, if she smokes she
has a greater risk of miscarriage.
Alcohol consumption - a woman's pregnancy can be seriously
affected by any amount of alcohol consumption. Alcohol abuse may lower male
fertility. Moderate alcohol consumption has not been shown to lower fertility
in most men, but is thought to lower fertility in men who already have a low
sperm count.
German scientists have reported that a virus
called Adeno-associated virus might have a role in male
infertility, though it is otherwise not harmful.
The following causes of infertility may only
be found in females. For a woman to conceive, certain things have to happen:
1: intercourse must take place around the
time when an egg is released from her ovary;
2: the system that produces eggs has to be
working at optimum levels; and her hormones must be balanced.
For women, problems with fertilisation arise mainly from either structural
problems in the Fallopian tube or uterus or problems releasing eggs.
Infertility may be caused by blockage of the Fallopian tube due to
malformations, infections such as chlamydia and/or scar tissue.
For example, endometriosis can cause infertility with the growth
of endometrial tissue in the Fallopian tubes and/or around the ovaries.
Endometriosis is usually more common in
women in their mid-twenties and older, especially when postponed childbirth
has taken place.
Another major cause of infertility in women
may be the inability to ovulate.
Malformation of the eggs themselves may complicate conception. For
example, polycystic ovarian syndrome is when the eggs only partially developed within the
ovary and there is an excess of male hormones. Some women are infertile
because their ovaries do not
mature and release eggs. In this case synthetic FSH by injection or Clomid (Clomiphene
citrate) via a pill can be given to stimulate follicles to mature in the
ovaries.
Other factors that can affect a woman's
chances of conceiving include being overweight or underweight, Being obese or
overweight - in
industrialized countries overweight/obesity and a sedentary lifestyle are
often found to be the principal causes of female infertility. An overweight
man also has a higher risk of having abnormal sperm or age as female fertility declines after the age of 30.
Submucosal fibroids - benign or non-cancerous tumors found in the muscular
wall of the uterus, occurring in 30% to 40% of women of childbearing age.
They may interfere with implantation. They can also block the fallopian tube,
preventing sperm from fertilizing the egg. Large submucosal uterine fibroids may make the uterus' cavity bigger, increasing the
distance the sperm has to travel.
§ Endometriosis - cells that are normally found within
the lining of the uterus start growing elsewhere in the body.
§ Previous sterilization treatment - if a woman chose to have her
fallopian tubes blocked. It is possible to reverse this process, but the
chances of becoming fertile again are not high.
Medications
Some drugs can affect the fertility of a
woman. These include:
§ Chemotherapy - some medications used in chemotherapy can result in ovarian failure. In some cases, this side
effect of chemotherapy may be permanent.
Radiotherapy
If radiation therapy was aimed near the womans reproductive
organs there is a higher risk of fertility problems.
Illegal
drugs
Some women who take marijuana or cocaine may
have fertility problems.
Sometimes it can be a combination of
factors, and sometimes a clear cause is never established.
Males
The main cause of male infertility is
low semen quality. In men who have the necessary reproductive
organs to procreate, infertility can be caused by low sperm count due to
endocrine problems, drugs, radiation, or infection. There may be testicular
malformations, hormone imbalance, or blockage of the man's duct system.
Although many of these can be treated through surgery or hormonal
substitutions, some may be indefinite. Infertility associated with
viable, but immotile sperm may be caused by primary ciliary dyskinesia.
Abnormal semen is responsible for about 75%
of all cases of male infertility. Unfortunately, in many cases doctors never
find out why. The following semen problems are possible:
§ Low sperm count (low concentration) - the man
ejaculates a lower number of sperm, compared to other men. Sperm
concentration should be 20 million sperm per milliliter of semen. If the count
is under 10 million there is a low sperm concentration (subfertility).
§ No sperm - when the man ejaculates and there is no sperm in the
semen.
§ Low sperm mobility (motility) - the sperm cannot
"swim" as well as it should.
§ Abnormal sperm - perhaps the sperm has an unusual
shape, making it more difficult to move and fertilize an egg.
Sperm must be the right shape and able to
travel rapidly and accurately towards the egg. If the sperm's morphology
(structure) and motility (movement) are wrong it is less likely to be able to
reach the egg and fertilize it.
Causes
of abnormal semen
§ Testicular infection
§ Testicular cancer
§ Testicular surgery
§ Overheating the testicles - frequent saunas, hot tubs, very hot
baths, or working in extremely hot environments can raise the temperature of
the testicles. Tight clothing may have the same effect on some people.
§ Ejaculation disorders - for some men it may be difficult to
ejaculate properly. Men with retrograde ejaculation ejaculate semen into the
bladder. If the ejaculatory ducts are blocked or obstructed the man may have
a problem ejaculating appropriately.
§ Varicocele - this is a varicose vein in the scrotum that may cause the
sperm to overheat.
§ Undescended testicle - one (or both) testicle fails to
descend from the abdomen into the scrotum during fetal development. Sperm
production is affected because the testicle is not in the scrotum and is at a
higher temperature. Healthy sperm need to exist in a slightly lower-than-body
temperature. That is why they are in the scrotum, and not inside the body.
§ Hypogonadism - testosterone deficiency can result in a disorder of
the testicles.
§ Genetic abnormality - a man should have an X and Y
chromosome. If he has two X chromosomes and one Y chromosome (Klinefelter's
syndrome) there will be an abnormal development of the testicles, low
testosterone, and a low sperm count (sometimes no sperm at all).
§ Mumps - this viral infection usually affects young children.
However, if it occurs after puberty inflammation of the testicles may affect sperm
production.
§ Hypospadias - the urethral opening is at the
underside of the penis, instead of its tip. This abnormality is usually
surgically corrected when the male is a baby. If it is not the sperm may find
it harder to get to the female's cervix. Hypospadias occur in about 1 in
every 500 newborn boys.
§ Cystic fibrosis - Cystic fibrosis is a chronic disease
that affects organs such as the liver, lungs, pancreas, and intestines. It
disrupts the body's salt balance, leaving too little salt and water on the
outside of cells and causing the thin layer of mucus that usually keeps the
lungs free of germs to become thick and sticky. This mucus is difficult to
cough out, and it clogs the lungs and airways, leading to infections and
damaged lungs. Males withcystic fibrosis commonly have a missing or obstructed
vas deferens (tube connecting the testes to the urethra; it carries sperm
from the epididymis to the ejaculatory duct and the urethra).
§ Radiotherapy - radiation therapy can impair sperm
production. The severity usually depends on how near to the testicles the
radiation was aimed.
§ Some diseases - the following diseases and
conditions are sometimes linked to lower fertility in males: Anemia,
Cushing's syndrome, Diabetes, Thyroid disease.
Combined infertility
In some cases, both the man and woman may be
infertile or sub-fertile, and the couple's infertility arises from the
combination of these conditions. In other cases, the cause is suspected to be
immunological or genetic; it may be that each partner is independently
fertile but the couple cannot conceive together without assistance.
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