Air Pollution May Impact Fertility
Source article: Wieczorek, K., Szczęsna, D., Radwan, M. et al. Exposure to air pollution and ovarian reserve parameters. Sci Rep 14, 461 (2024). https://doi.org/10.1038/s41598-023-50753-6
Environmental pollution in human health
Hazardous substances such as chemicals and other substances from both natural and man-made sources can pollute our environment. Exposure across short and long time scales can impact body functioning and increase risk of different diseases. This can include asthma, hay fever, and other allergic diseases, with some volatile organic compounds causing eye, nose, and throat irritation, headaches, nausea, and loss of coordination. Furthermore, prolonged exposure may cause damage in the liver, brain and digestive systems, and in certain circumstances, it can result in cancer. In this article, we will discuss the possible impact of pollution on female reproductive organs.
Understanding the impact of air pollution on ovarian health
Have you ever asked yourself if environmental pollution can affect reproduction? Well, you are not the only one. Environmental pollution is a global problem and its health impacts have been well-studied. The main associated diseases are cardiovascular and respiratory diseases. Additionally the impact of pollution on fertility in men was measured by diverse groups showing that pollution can affect the quality of sperm. In women, pollution may lead to higher miscarriage rates, risk of stillbirth, and decreased ovarian reserve.
Recently, in 2024, Wieczorek and collaborators wanted to discover if there is a relationship between exposure to ambient air pollution and ovarian reserve.
The importance of ovarian reserve
Ovarian reserve refers to the number and quality of eggs present in a woman’s ovaries. It naturally declines with age, but environmental factors can also play a role. Scientists measure ovarian reserve using specific parameters, such as Anti-Müllerian Hormone (AMH) levels, antral follicle count (AFC), and other hormonal markers. AFC and AMH are both markers used to assess a woman’s ovarian reserve, which reflects the quantity of eggs remaining in the ovaries.
Main focus of the study
To find the response to their initial question (Is there an environmental impact on ovarian reserve), the researchers analyzed blood samples and ovarian ultrasonography (USG) of women attending to a fertility clinic. Women were living in areas with varying levels of air pollution, with diverse pollutants, including ozone and those small particles suspended in the air called particulate matters (PM). They took the mean of each one of the pollutants measurements i.e. PM2.5 levels, ozone, and so on (obtained from the National Environmental Protection Inspectorate) after 6 months. This specific period was chosen to align with the maturation of the primary follicle to antral follicle.
Key findings
The study found that higher exposure to certain air pollutants, especially fine particulate matter (PM2.5), was associated with decreased levels of AMH and lower AFC. These changes suggest a reduction in ovarian reserve, which could potentially impact fertility. Women exposed to higher pollution levels tended to have fewer eggs and lower hormonal indicators of ovarian health. Moreover, women older than 35 years of age, were particularly sensitive to PM2.5
Implications for women’s health
These findings are significant because they highlight an environmental factor that could influence reproductive lifespan and fertility potential. While age remains the most critical factor in ovarian reserve decline, environmental exposures like air pollution might accelerate this process or contribute to earlier reproductive aging.
Why air pollution affected fertility?
Even though the mechanisms by which pollutants damage ovarian reserve are not fully understood, several processes may be related. Pollutants can increase oxidative stress and cause damage to ovarian cells; the DNA within them can even be affected, leading to apoptosis (cell death). A reduction in the number of cells, or damaged cells due to genetic or epigenetic changes, can directly impact fertility. Moreover, some pollutants act as endocrine disruptors, altering the proper interactions between hormones and their receptors and, as a consequence, their function.
Final thoughts
The study teaches us the importance of reducing exposure to air pollution, especially for women planning to conceive or those in reproductive age. Public health policies aimed at improving air quality could have benefits beyond respiratory health, extending to reproductive well-being.
While more research is needed to fully understand the mechanisms and long-term effects, even that, this study highlights that our environment plays a crucial role in reproductive health. Protecting ourselves from air pollution is not only vital for our lungs and heart but also for maintaining healthy ovarian function and fertility.
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