From Falling Sperm Counts to Hormonal Disruptions: Climate Change’s Reproductive Toll

Climate change is no longer just about melting ice caps or rising seas — it is beginning to alter human biology.

As heatwaves intensify and air quality deteriorates, doctors are seeing growing evidence that the climate crisis is quietly undermining fertility in both men and women.

How Heat and Pollution Are Altering Reproductive Health

Women’s reproductive hormones are highly sensitive to temperature changes, says Dr Arvind Vaid, Gynaecologist & IVF Specialist, Indira IVF, Delhi. “Elevated heat disrupts hormones like LH, FSH and GnRH, affecting egg development, embryo growth and even fetal health,” he explains. Heat exposure during pregnancy also increases miscarriage, stillbirth and low-birth-weight risks.

Men face similar threats.
“High temperatures impair spermatogenesis, reduce sperm count and increase DNA damage,” notes Dr Hina Shaikh, Consultant Gynaecologist & Obstetrician, Fortis Hiranandani Hospital, Navi Mumbai. Heatwaves — now more frequent due to climate change — sharply affect sperm motility and morphology.

Air pollution is compounding the damage.
According to Dr Vaid, worsening air quality “raises pregnancy loss rates and lowers fertility.”
Dr Shaikh warns that endocrine-disrupting chemicals in polluted air, water and food can “reduce sperm count, degrade egg quality and disturb puberty timing.”

Nutrition, Disease and IVF Outcomes Also at Risk

Climate instability is also reshaping nutrition and infectious disease patterns — both critical to fertility.

“Extreme weather affects crop yields and contributes to micronutrient deficiencies like zinc, selenium and iron, which are essential for reproductive health,” says Dr Shaikh.

Rising temperatures are expanding the reach of diseases such as dengue, malaria and Zika. These infections, she notes, are linked to infertility, pregnancy complications and congenital abnormalities.

For couples seeking fertility treatment, the environment matters too. Poor air quality can reduce IVF success rates and lead to failed embryo transfers, says Dr Vaid.

The Psychological Fallout
Extreme weather events drive chronic stress — another silent fertility disruptor.
“Prolonged stress elevates cortisol, which interferes with normal reproductive function,” Dr Shaikh adds.