hehehe....About 30 per cent of women of reproductive age and 35 per cent of men in the United States smoke cigarettes.
This is in spite of the long-standing
campaigns to limit tobacco smoking. Several studies have shown a causal
link between cigarette smoking and infertility.
A study published by the United States
Centers for Disease Control and Prevention showed that while smoking
rates among women in the western world have fallen recently, it still
remains a major cause of newborn deaths, preterm births and babies with
low birth weight.
A systematic review of the scientific
literature on the impact of cigarette smoking and smoke constituents
revealed that all stages of reproductive functions are targets of
cigarette smoke toxicants.
In the United Kingdom alone, smoking in
pregnancy is responsible for about 5,000 miscarriages, 3,000 peri-natal
deaths and approximately 2,000 premature births each year.
The WHO states that smoking causes more
deaths in one year than all of these combined: deaths due to HIV,
illegal drug use, alcohol use, motor vehicle injuries and fire-related
incidents.
Smoking causes about 80 per cent of
deaths from COPD and 10 per cent of all lung cancers in males and
females. More people die from lung cancer each year than from breast
cancer.
It cannot be overemphasised that
research has established a causal relationship between infertility and
smoking. It’s been proved that women who smoke take longer to conceive
than women who do not smoke. Some studies found out that tobacco use
affects the receptivity of the uterus particularly among heavy smokers.
There’s also a higher incidence of
ectopic pregnancies among smokers. Comparatively, low-level smoking,
‘sidestream’ and passive smoking can have detrimental effects on
fertility. Recent evidence suggests that smoking affects the success
rate of fertility treatment.
Research has also depicted that women
undergoing assisted reproductive treatment have a significant negative
outcome compared to non – smokers. A study even showed a 50 per cent
decline in implantation rate in smokers.
The impact of tobacco compounds in the
process of ovarian follicle maturation is expressed by worse IVF
parameters in cycles performed on women with smoking habits. This as
well as uterine receptiveness and tubal function are significantly
altered by the smoking habit.
Smoking has also been implicated to
cause a reduction in the number of germ cells (sperm and egg forming
cells) and somatic cells (cells that form the body parts) in utero. It
can also affect protamine, a protein essential for sperm production.
Males born to women who smoked in
pregnancy are at risk of having small testes, low sperm counts, and low
sperm concentration. These men also have a high number of malformed
sperm. Nicotine by-products have been traced in the semen of such men
and have been found to reduce sperm motility and their fertilisation
potential.
The effects of smoking and alcohol
consumption, consequent of our lifestyle and social behavior, have over
the years been proved to have deleterious effects on fertility and have
been implicated in early pregnancy losses, preterm births and low birth
weight babies.
Women who smoke have been observed to
reach menopause a year or four earlier than non-smokers, shortening
their reproductive lifespan. Scientists have said the effects of tobacco
on infertility may be ultimately related to oxidative effects.
In females, smoking potentially affects
the ovaries adversely. The degree of damage is dependent upon the
quantity and length of time a woman smokes. Nicotine and other hazardous
substances in cigarette interfere with the body’s ability to create
oestrogen, a hormone that regulates follicular growth and ovulation.
Smoking interferes with folliculogenesis, embryo transplant, endometrial
receptivity, endometrial angiogenesis, uterine blood flow and the
uterine endometrium. Smokers are 60 per cent more likely to be infertile
than non – smokers.
Smoking decreases the chances of IVF
producing a live birth by 34 per cent and increases the risk of an IVF
pregnancy miscarrying by 30 per cent. Some damage is irreversible, but
stopping smoking can prevent further damage.
In males, oxidative stress occurs in the
seminal fluid of smokers. Increased concentrations of cadmium, lead and
ROS are significantly higher; and at the same time, concentrations of
ascorbic acid and the activity of other components of the antioxidant
defence are significantly reduced. Ascorbic acid is the principal
extracellular water – soluble antioxidant. Therefore, the scavenging
capacity of the antioxidant defence system is severely impaired.
Incidence of impotence is approximately
85 per cent higher in male smokers compared to non- smokers and is a
major cause of erectile dysfunction (ED). Smoking causes impotence by
encouraging arterial narrowing.
Fathers who smoke heavily (greater than
20 sticks per day) at the time of conception increases the child’s risk
of childhood leukaemia and shortens the reproductive life span of their
daughters.
Evidence has also suggested that female
infertility can be damaged in utero if the woman’s mother was exposed to
second hand smoke while pregnant. It has also been found that women
exposed to cigarette smoke while undergoing IVF or other assisted
reproduction technologies treatment can experience adverse pregnancy
outcomes. More epidemiological research is needed to buttress these
suggestions.
Second-hand tobacco smoke is a known
reproductive toxin comprising a mixture of at least 4,000 chemical
compounds. Non-smokers who are exposed to second-hand smoke are at the
risk of difficulty becoming pregnant; having spontaneous abortion;
having babies with congenital malformations or giving birth to still
births. Chemicals in tobacco smoke alter endocrine functions which in
turn affects the release of pituitary hormones. This endocrine
disruption is thought to contribute to adverse outcomes including early
menopause.
Smoking can also reduce the chances of a
woman becoming pregnant and can affect her baby’s health before (in
utero) and after (postpartum). It is also implicated to affect man’s
sperm, thereby reducing fertility and increasing the risks of birth
defects and miscarriages. This it does by damaging sperm DNA.
Smoking is one of the main causes of
infertility. Many men and women of reproductive age continue to smoke
with only a small proportion of them considering quitting. Women,
particularly when pregnant, attempt to quit than at any other times
during their lives. Support should come from the baby’s father, family
members and friends as well as the health care system e.g. pregnancy
smoking helpline, smoking cessation groups, etc.
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