Medical Director, Consultant
Gynaecologist, MB ChB FRCOG
Trinidad & Tobago IVF and Fertility Centre
info@TrinidadIVF.com
When couples struggle to conceive, the focus almost always turns to women. Women’s age. Women’s hormones. Women’s bodies. But after more than two decades as a fertility doctor, I can tell you plainly: It takes two to make a baby and the conversation should include men equally. And when having this conversation on April 7th, World Health Day, we need to talk about how climate change is affecting male fertility – and how that evidence should spur us to action.
In over half the couples I see, male infertility is the problem, either as the main issue or as part of a more complicated picture. Regardless, male fertility matters far more than people realise.
A young couple in their early thirties – Kareem and Kayla (not real names) – was in my clinic today. Kareem, confused and frustrated, said, “I do everything right, doctor! I don’t smoke, I barely drink, I exercise, and I eat healthily. So why are we having so much trouble getting pregnant?”
His sperm test showed low numbers, poor swimming and higher rates of abnormally shaped sperm. No obvious cause; no infection, no obvious medical condition, hormones normal. We talked about the causes of his issue, but they weren’t what he expected. This is a conversation I have daily with many of the thousands of couples we help in the clinic.
Unlike many illnesses, sperm damage doesn’t cause pain or physical symptoms. A man can feel healthy, eat well, exercise regularly, and still have unhealthy sperm. Like Kareem, most men are completely unaware of problems until they decide to start a family.
My answer to Kareem’s question was to look at our planet and the way we’ve damaged it. Climate change is real, and now, scientists are finding signs that it is harming men’s fertility.
Ten years ago, I was sceptical. Like many doctors, I thought heat waves were only dangerous if you were caught in the middle of them, not something linked directly to the infertility problems I saw in my patients.
Today, the science has convinced me.
Sperm are like smoke before the fire, often the first cells to hint at health problems. Sperm are very temperature-sensitive; they develop and function best at lower temperatures (this is why testicles hang outside the body). Disrupt this balance long enough, and sperm quality can suffer.
Prolonged Heat Exposure + Polluted Air = Sperm Damage
Large international studies show that when temperatures rise above normal, sperm quality tends to fall, and sperm numbers drop. What’s important here isn’t just extreme heat, but prolonged exposure to that heat. It isn’t one hot afternoon that matters, but weeks of sustained heat where the body never fully cools down.
The second issue is that the polluted air we breathe every day — from bush fires, Sahara dust and car emissions — contains toxic particles which pass easily through our lungs into our bloodstream, triggering inflammation and oxidative stress throughout the body. Solid research data shows that increasing air pollution triggers lower sperm counts, poorer swimming, more abnormal shapes, and higher levels of DNA damage.
At the Trinidad & Tobago IVF and Fertility Centre, we are increasingly seeing the cumulative effect of men’s lifestyle choices colliding with climate change-induced male infertility issues. Many men are already vulnerable to infertility due to age, poor diet, obesity and diabetes. In T&T, about one in every five to six couples (all backgrounds and ethnicities) will struggle to get pregnant. Sperm are the human race’s genetic messengers – their mission is to deliver their DNA package into the egg, creating the next generation. Damaged sperm DNA is causing male infertility and potential problems for the next generation, but the good news is that there is plenty you can do to change that.
Here are six steps to help protect sperm health:
Take heat seriously: During prolonged hot periods, prioritise cooling and ensure good hydration with water. Wear loose, breathable clothing in natural fabrics.
Air quality matters: On high pollution or smoky days, limit time outside, especially avoiding heavy outdoor exercise.
Know your numbers: Do a sperm test and consider an advanced sperm test for DNA damage. Male infertility has no symptoms, and some damage won’t show up on routine sperm tests.
* Understand timing: If you and your partner still aren’t getting pregnant after a normal sperm test, retest three months later. One test is a snapshot, not a verdict.
Expert testing: Accurate sperm testing requires a qualified andrologist (laboratory technician trained to perform sperm assessments) in a fertility lab. Prioritise expert fertility advice and see a fertility specialist.
Eat healthy: Commit to a diet rich in fruits, vegetables, whole foods, and home-cooked meals. Avoid fast food, soft drinks, and ultra-processed foods.
Don’t wait!: Men have biological clocks too! If having children is important to you, sooner is better than later.
Do your part to save our environment – after all, we’re fighting for human fertility and the next generation.
The foregoing is a weekly column by EarthMedic and EarthNurse NGO to help readers understand and address the climate and health crisis.
