The European Society of Human Reproduction and Embryology (ESHRE) Annual Meeting took place in Vienna last week. Today we examine an interesting abstract on the effects of air pollution on fertility.
When you think of air pollution, what springs to mind?
Images of heavy London smog?
Hazy sunsets over Tokyo?
The belching chimneys of heavy industry?
Or highways of stationary vehicles all doing their best to warm the planet by a few degrees?
That all seems comfortably remote, but the truth is that air pollution has a significant impact on public health. In fact, poor air quality is the largest environmental risk to public health in the developed world.
For instance, in the UK alone, a 2010 report by the UK’s Environment Audit Committee considered that the cost of health impacts of air pollution was likely to exceed a sum in excess of $12Bn.
What’s the problem?
It is well known that long-term exposure to air pollution reduces life expectancy, due to cardiovascular, respiratory diseases and lung cancer.
However, short-term exposure over hours or days to elevated levels of air pollution can also cause a range of problems. These include effects on lung function, exacerbation of asthma, increases in respiratory and cardiovascular hospital admissions and mortality.
What has this got to do with fertility?
According to a new study presented at ESHRE, high levels of air pollution can negatively affect ovarian reserve. Ovarian reserve refers to the number of resting follicles in the ovary and marks the potential female fertility.
We know that smoking is a form of pollution and has an adverse effect on fertility. The chemicals in smoke have the potential to disturb the creation and role of hormones, the all-important messenger molecules in the reproductive system.
The research
Researchers from the University of Modena, Italy, studied hormone measurements from more than 1300 Italian women over 10 years. They looked at the anti-Mullerian hormone (AMH), which is a hormone made by cells in the ovaries. This is a reliable marker of the ovarian reserve.
They compared AMH levels to patients’ age and the amount of air pollution at the patients’ residential addresses. Factors they considered included daily particulate matter (PM), which is produced by diesel-burning vehicles. They also looked at the level of nitrogen dioxide (NO2), a polluting gas that gets into the air from burning fuel.
The researchers found that AMH levels were lowered by both PM and NO2, and that this effect was not related to the age of the patients.
Professor Antonio La Marca, who led the study said, “The influence of age and smoking on AMH serum levels is now largely accepted. But a clear effect of environmental factors has not been demonstrated so far. The study confirms that independent of age, the higher the level of particulate matter and NO2, the lower the serum concentration of AMH. Living in an area associated with high levels of air pollutants in our study increased the risk of severely reduced ovarian reserve by a factor of 2 or 3.”
So a move to the country away from the smoke and smog, may indeed promote fertility and now we may know one of the scientific reasons why.
Further reading: Abstract O-204. ESHRE Meeting. Vienna 2019
