By Chioma Umeha, Taiwo Orebamjo
Infertility refers to an inability to conceive
after having regular unprotected sex. Infertility can also refer to the
biological inability of an individual to contribute to conception, or to a
female who cannot carry a pregnancy to full term. In many countries infertility
refers to a couple that has failed to conceive after 12 months of regular
sexual intercourse without the use of contraception.
Studies indicate that slightly over half of all
cases of infertility are a result of female conditions, while the rest are
caused by either sperm disorders or unidentified factors.
In Europe, Nigeria and other part of the world, approximately 85 per cent of couples will conceive within one
year if they have regular unprotected sex. It is estimated that
20 per cent of couples will
conceive within one month; 70 per cent will conceive within six months; 85 per cent will conceive within 12 months; 90 per cent will conceive
within 18 months, while 95 per cent will conceive within 24 months.
Therefore, doctors will not usually diagnose a
couple as infertile until 24 months have passed without conception and regular
unprotected sex. Most people will see their general practitioner (GP) primary
care physician if there is no
pregnancy within 12 months.
According to the National Health Service, UK, a
couple that has been trying to conceive for over three years has a maximum 25
per cent chance of conceiving over the subsequent 12 months if they continue
trying.
In medicine, a risk factor is something that
raises the risk of developing a condition, disease or symptom. For example,
obese people are more likely to develop diabetes type 2 compared to people of
normal weight; therefore, obesity is a risk factor for diabetes type 2.
AGE – a woman’s fertility starts to drop after she
is about 32 years old, and continues doing so. A 50-year-old man is usually
less fertile than a man in his 20s (male fertility progressively drops after
the age of 40).
SMOKING – 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.
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 has a higher risk
of having abnormal sperm.
EATING DISORDERS – women who become seriously
underweight as a result of an eating disorder may have fertility problems.
BEING VEGAN – if you are a strict vegan you must
make sure your intake of iron, folic acid, zinc and vitamin B-12 are adequate,
otherwise your fertility may become affected.
OVER-EXERCISING – a woman who exercises for more
than seven hours each week may have ovulation problems.
NOT EXERCISING – leading a sedentary lifestyle is
sometimes linked to lower fertility in both men and women.
SEXUALLY TRANSMITTED INFECTIONS (STIs) – chlamydia
can damage the fallopian tubes, as well as making the man’s scrotum become
inflamed. Some other STIs may also cause infertility.
EXPOSURE TO SOME CHEMICALS – some pesticides,
herbicides, metals (lead) and solvents have been linked to fertility problems
in both men and women.
MENTAL STRESS – studies indicate that female
ovulation and sperm production may be affected by mental stress. If at least
one partner is stressed it is possible that the frequency of sexual intercourse
is less, resulting in a lower chance of conception.
Causes of infertility in women:
There are many possible causes of infertility.
Unfortunately, in about one-third of cases no cause is ever identified.
Ovulation disorders – Problems with ovulation are
the most common cause of infertility in women, experts say. Ovulation is the
monthly release of an egg. In some cases the woman never releases eggs, while
in others the woman does not release eggs during come cycles.
Ovulation disorders can be due to:
– Premature ovarian failure – the woman’s ovaries
stop working before she is 40.
– PCOS (polycystic ovary syndrome) – the woman’s
ovaries function abnormally. She also has abnormally high levels of androgen.
About five per cent to 10 per cent of women of reproductive age are
affected to some degree. Also called Stein-Leventhal syndrome.
– Hyperprolactinemia – if prolactin levels are
high and the woman is not pregnant or breastfeeding, it may affect ovulation
and fertility.
– Poor egg quality – eggs that are damaged or
develop genetic abnormalities cannot sustain a pregnancy. The older a woman is
the higher the risk.
– Overactive thyroid gland
– Underactive thyroid gland
– Some chronic conditions, such as AIDS or cancer.
Scientists discover gene that may explain
infertility
Scientists from the University of Edinburgh
reported in the Journal of Cell Science that they identified a gene that
controls a vital process in the formation of healthy fertile eggs.
They say their breakthrough will help researchers
better understand how cells divide during reproduction, which in turn will help
explain low fertility and sterility.
Problems in the uterus or fallopian tubes
The egg travels from the ovary to the uterus
(womb) where the fertilized egg grows. If there is something wrong in the
uterus or the fallopian tubes the woman may not be able to conceive naturally.
This may be due to:
Surgery – pelvic surgery can sometimes cause
scarring or damage to the fallopian tubes. Cervical surgery can sometimes cause
scarring or shortening of the cervix. The cervix is the neck of the uterus.
Submucosal fibroids – benign or non-cancerous
tumors found in the muscular wall of the uterus, occurring in 30 per cent to 40 per cent 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. However, an
eight-year study showed tubal reversal surgery results in higher pregnancy and
live birth rates and is less costly than IVF.
