Declining Fertility Rates In India: Are Air Pollution, Heat, Or Stress The Biggest Health Threats?

There is a mass transformation in India's fertility landscape as the dwindling fertility rate is raising alarm bells. Non-communicable diseases are increasingly recognized as a significant factor in the declining fertility rates in India, alongside behavioural and lifestyle determinants. Recent research by the United Nations Population Fund (UNFPA), the Indian Ministry of Health and Family Welfare, and others have confirmed that India's fertility rate is dropping, with major new contributors being air pollution, heat, and chronic stress. While all these factors contribute to the low fertility rate, air pollution is the first definite threat whose impact is measurable in terms of its impact on the systemic reproductive system in major Indian cities.

India's Total Fertility Rate has seen a historic drop, reaching the replacement level of 2.0 as per the National Family Health Survey-5 (2019-21) and continuing to decline to 1.9 by 2023 in the Sample Registration System report. While this signals success in family planning, a growing body of Indian research suggests that environmental and lifestyle factors like air pollution, extreme heat, and chronic stress are quietly contributing to reproductive challenges, potentially pushing the fertility rate further down and impacting the quality of overall reproductive health.

Air Pollution Effects On Fertility

When it comes to explaining the impact of air pollution on male fertility rates, the need to understand how particulate matter 2.5 enters the bloodstream needs to be comprehended. The fine particulate matter causes oxidative stress, which lowers sperm count and causes irreparable damage to the DNA.

In the review from Environmental Health (2021), the direct correlation between breathing in particulate matter 2.5 to a direct lowering of sperm count in the male population is present.

Another research piece from All Indian Medical Sciences (2020) found a significant link between high exposure to PM2.5 (fine particulate matter) and a 15-20% reduction in sperm count. This proves that exposure to pollutants like vehicle emissions and industrial chemicals can damage sperm DNA, directly compromising the state of male reproductive health.

The impact on air pollution is not limited to male fertility, as female fertility and pregnancy are also deeply effected by the rampant air pollution. The deferential effects on pregnancy can be as follows:

• Hormonal Disruption: the sensitive period of pregnancy requires a hormone level that is responsible for a proper environment for fetal development.
• Reduced Ovarian Reserve: This means that the level of eggs in the ovaries may be reduced in quantity, thus reducing the chances of pregnancy.
• Other Risks: The increased chances of miscarriage, low birth weight, and preterm births can endanger the quality of life of the fetus is possible.

Heat Stress

The two major factors that effect male and female fertility are primarily heat and chronic stress, which are common in the tropical temperate climate of India. The thermal stress from the extreme heat hinders the biological mechanism of spermatogenesis that requires cooler temperatures, below 2-3 degrees Celsius.

There is a direct link between extreme heatwaves in Central India, as it is near the equator for causing a temporary drop in the ability to reproduce.

Research in The Lancet Planetary Health (2020) suggested that prolonged heat exposure may reduce the likelihood of conception in women by 10-20%, particularly in rural areas without access to cooling. Whereas extreme heat exposure in the first trimester is associated with a higher risk of miscarriage and preterm birth, according to the Indian Journal of Public Health.

Chronic Lifestyle Stress

The structure of corporate India has long working hours, which poses significant challenges to have their own families while juggling a career. This, coupled with parenthood, directly effects the fertility rates in India. While other issues, like limited access to paid childcare, cause extreme stress on the minds of people.

Chronic stress disrupts the hypothalamic-pituitary-gonadal axis, which negatively effects the reproductive hormone balance.

While age and chronic stress remain key factors that impact fertility rates. The most significant factor is air pollution, which poses a pervasive, unavoidable public health hazard effecting even healthy individuals. In order to curb the pollution from air pollution in India, it is important for the system to take action along with measures that can be adopted by individuals. The persistent air pollution is an acute but persistent environmental toxin layered on top of lifestyle stress.

Practical Ways To Protect Your Fertility

There are a number of ways through which you can protect your fertility; these ways are as follows:

Even the United Nations has flagged the global fertility crisis and where India stands, and the factors that are causing it. It is imperative to be proactive to act before it is too late. For the health of the next generation, policy must move beyond simple family planning goals to actively address these silent, environmental health crises, while also supporting parents with work-life balance and affordable childcare options.

Disclaimer: This content, including advice, provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.

References:

Jana, A., Singh, B. K., & Singh, G. (2025). In-utero exposure to PM 2.5 and adverse birth outcomes in India: Geostatistical modelling using remote sensing and demographic health survey data 2019-21. PLOS Global Public Health, 4(2), e0002875.

Ministry of Health and Family Welfare, Government of India. (2022). National Family Health Survey (NFHS-5) 2019-21: India.

Office of the Registrar General & Census Commissioner, India. (2023). Sample Registration System (SRS) Statistical Report 2020. Ministry of Home Affairs.

Research on Air Pollution and Sperm Quality. (2020). All India Institute of Medical Sciences (AIIMS) & CSIR-National Environmental Engineering Research Institute (NEERI).

The Lancet Countdown on Health and Climate Change. (Various Years). Tracking progress on health and climate change.

Varghese, P. S., Balasubramanian, S., & Ponnampalath, V. (2019). Elevated levels of bisphenol A in human samples in India: A health concern. Environmental Science and Pollution Research, 26, 32800-32808.

World Health Organization (WHO). (2020). Impact of climate change and heat on human reproductive health.