Passive Smoking and Fertility
Passive smoking and reproductive health
In November 2010, there was a comprehensive report on the global effects of passive smoking published in the prestigious medical journal The Lancet. Statistics can be tiresome and at their worst can hide the real toll on the individual lives of those affected as they are reduced to just a number but, consider this: Globally, over 600,000 deaths every year are directly attributable to passive smoking. Each one of those 600,000 is an individual; like you and me, with a life, loved ones, ambitions and goals to achieve. Each one of those, literally cut down by somebody's or some other people’s habits. In this hub, we are looking at the effects of passive smoking on reproductive health.
Smoking and having babies
When the woman herself smokes, there are potential consequences if she is actively trying to conceive or is already pregnant. Let’s quickly look at those:
- Increased risk of ectopic pregnancy (pregnancy outside the womb)
- Increased risk of intrauterine growth restriction (IUGR)
- Increased risk of stillbirth
- Increased risk of preterm delivery
- Increased risk of perinatal death for the baby
- After the birth, for the baby; increased risk of sudden infant death syndrome (cot-death)
- A much higher risk of the child suffering from ‘glue ear’ (a hearing impediment)
Passive smoking and pregnancy
So what if the pregnant woman herself is a non-smoker but she lives in an environment where there is a lot of cigarette smoke? In Europe and North America, authorities have taken active steps to ensure people are protected from other people’s smoke. It is virtually impossible to find any public places where smoking is still allowed and this has gone a long way in protecting non-smokers. Sadly, this is still not the case in many other countries and working pregnant women remain victims of this. And then, there is the home. This is still a major source of passive smoking even in the western world. Women (and men) need to be aware of the consequences of passive smoking on reproductive health
It is the dude...
A man who smokes should be aware that he is reducing his partner’s chances of successful conception. Smoking affects the DNA and there is reduced binding of the sperm to the egg. This is apart from the well-known reduced sperm count.
A large study from a decade ago showed definite reduction in fertility when the male partner is a smoker. The higher the number of cigarettes smoked daily, the lower the chances of successful conception. This study, the results of which have since been reproduced in several other studies, showed that if the man smoked 20 cigarettes or more, his live-in partner’s chances of conception were reduced by a third (34%)
Research shows that if a woman is undergoing fertility treatment in the form of in vitro fertilisation (IVF), her chances of success are significantly reduced if exposed to second hand smoke. A large Canadian study published in 2005 showed that pregnancy rate (per embryo transfer) among non-smokers averaged 48%. For women who smoked it was less than half at 19% and for those exposed to second-hand smoke (i.e. passive smokers), it was more or less similar at 20%. It is therefore the case that, even if the woman herself is a non-smoker, if her partner smokes, her chances of success are more than halved. The practical (and financial) meaning of this is that, on average, it takes twice the number of IVF attempts for smokers and those exposed to second-hand smoke to have success when compared to non-smokers.
Results of a study published in early 2011 show that women exposed to second hand smoke have rates of stillbirth 23% higher than average. That should make people stop and think. An increase of almost a quarter for this most devastating of pregnancy complications is not something to be taken lightly and there is more...
The same study quoted above showed that the rate of congenital birth defects is increased by 13% where there is passive smoking. This is lower than where the woman herself is a smoker but it is still a significant increase.
Long term consequences for the baby
It has been known for a while now that mothers who smoke during pregnancy, especially in the early trimester, negatively affect their offspring’s own fertility. A female baby whose mother smoked during pregnancy loses up to 40% of germ cells in her own ovaries. The germ cells are the ones that develop into eggs (ova). This reduction has been shown to adversely affect the fertility of the affected girl. In other words; mother smokes, daughter suffers from sub-fertility. Now, recent studies show a similar effect from passive smoking. The reality of the matter is, if the mother is not smoking but her live-in partner is or, if she is otherwise exposed to second hand smoke, the risks that come with smoking, as detailed above, remain.