Some scientists now call the human race an endangered species, facing its toughest challenge in history.

Birth rates are at an all-time low. Male live births are in decline. In the U.S., the birth rate is only 1.8. (It takes 2.1 for the population of any given area to remain stable.) In Hong Kong and South Korea, it’s 1.1.

Author Shanna H. Swan, Ph.D. writes that fertility should matter to everyone—whether they’re in their child-bearing years or not—because fertility has vast implications for a person’s overall health.

In other words, what’s good for your reproductive health benefits your heart, brain, and immune system too. And what’s bad can lead to a cascade of diseases, including heart disease and cancer.

In the book Count Down: How Our Modern World is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race, Prof. Swan explores what our plummeting birth rates mean for the future of humanity. Some of her findings are beyond alarming.

For example, male infertility is increasing almost universally.

Based on 185 studies of 42,935 men, total sperm counts have fallen more than 59 percent in the past 40 years. The World Health Organization deems a sperm count under 15M (million) to be “low.” Yet a Danish study found that levels under 40M thwart conception.

And sperm count isn’t the only factor. Vitality (percent of sperm that are alive) and morphology (size/shape) matter too. Studies show declines here also.

Sperm Banks are Running Low

Sperm banks paint a telling picture. They need healthy sperm. Yet they’re having trouble finding qualified donors.

In the U.S., 69 percent of potential donors made the cut in 2003. By 2013, only 44 percent did, despite improved lifestyle (exercise, diet, not drinking to excess.) In China, qualified donors collapsed from 56 percent in 2001 to 18 percent in 2015– a massive decrease.

By any measure, sperm aren’t doing well these days – though most men don’t realize this.

The author states that men don’t know the quality of their sperm determines their success in conception. They generally assume that they can impregnate their partner at will. But that’s not the new reality.

One hidden factor often goes unrecognized: low testosterone. A healthy testosterone level is essential for healthy sperm.

But don’t run out and get testosterone hormone replacement just yet. That lowers sperm count so much (even to zero!) that some promote it as a birth control method. This is because testosterone treatment decreases levels of another hormone called follicle-stimulating hormone (FSH), which is essential to sperm production. The good news is that, in most cases, male infertility caused by testosterone treatment is reversible.

Sperm decline presents a daunting threat to men, couples, and society.

As you can see, fertility challenges are an equal opportunity issue for both sexes. While a man may not hear his biological clock ticking, it’s ticking!

Hazards of Playing the Waiting Game

Some women are very aware of their own biological clock. Others aren’t.

Women are also losing good-quality eggs earlier than expected and having more miscarriages.

There’s compelling evidence of diminished ovarian reserve (DOR), which means a lower quality and/or quantity of eggs.

For example, the average 20-something today is less fertile than her grandmother was at age 35.

What’s bizarre is that fertility awareness is so low. Forty percent of women don’t know about the ovulatory phase of their menstrual cycle, which is the only time a woman can get pregnant.

For a woman to conceive, she needs healthy ovaries, eggs, fallopian tubes, uterus, and also ovulation.

Most infertility comes from ovulation disorders. Advancing age certainly plays a role. But conditions like polycystic ovary syndrome (PCOS), endometriosis, and fibroids also hinder fertility.

Female fertility has a “best-if-used-before date” of 35. Many women, an incredible 70 percent in one study, believe motherhood is possible after 40. But doctors urge caution, telling women not to count on it.

Furthermore, assisted reproductive technology is no panacea and it’s painful at any age for your body and your bank account.

Not “Better Living Through Chemistry”

For a long time, no one thought toxic chemicals in our air and water could have negative effects on birth rate.

Everyone thought the placenta created an impervious protective barrier—but it couldn’t be further from the truth.

Hormones are master manipulators, influencing almost every cell in the body.

Prenatal exposure to hormone-disrupting chemicals disturbs genital tract development, especially in males. Male babies are most vulnerable during the reproductive programming window between the eighth to twelfth weeks of the first trimester – when the genitals and future sperm-producing organs are being formed.

That’s why pregnancies with male babies are more prone to miscarriage. So instead of “better living through chemistry,” we got “more death through chemistry.”

Plenty of Blame to Go Around

Trends toward later marriage and diminished interest in sex contribute to the low birth rates, as do radiation from cell phones, laptops, Wi-Fi and microwaves, which can wreck sperm count, morphology, and motility.1

But Prof. Swan places major blame on one silent but ubiquitous threat to human fertility that we’ve written about a lot recently, plastics and modern chemicals.

Plastics are risky to fertility. They’re called “legacy chemicals” – precisely because they’re designed to last for generations.

One of their sneakiest harmful effects is endocrine disruption, or damaging your hormone function and levels.

Some Endocrine-Disrupting Chemicals (EDCs) act like imposter hormones. They bind to receptors where your natural hormones dock, tricking your body to respond to EDCs like they’re the real deal.

Phthalates, BPA, flame retardants, and pesticides pose significant harm to fertility. Phthalates have the strongest influence on males; BPA on females.

High phthalate levels correlate with lower sperm counts, malshaped sperm, and sperm self-destruction. Meanwhile, BPA is linked with decreased sperm quality and vitality.

Phtahlates in women can prevent egg release. BPA mimics estrogen, triggering reproductive problems and cancer.

Scientists also see ripple effects from plastics, meaning they can cause future health problems as well as infertility for your children, to the third and fourth generations.

Male sensitivity to EDCs causes a “male fertility death spiral” or a progressive decrease in sperm counts for generations. Which is beyond scary. This cataclysmic problem is why scientists worldwide are sounding the alarm.

How to Protect Your Fertility Today

Here’s a good rule of thumb: what’s good for your heart, brain, and immune system is also good for your reproductive health. The book offers these tips for safeguarding fertility for yourself or your loved ones:

  • Have babies when you’re younger, while time is on your side.
  • Steer clear of tobacco smoke.
  • Maintain a BMI of 20 to 25.
  • Avoid processed foods and choose organic foods to avoid pesticides.
  • Drink filtered water, from glass.
  • Use glass containers for leftovers and never ever use plastic in the microwave.
  • Trade vinyl shower curtains for cloth. Also, use cloth reusable shopping bags.
  • Switch to safe personal care products to avoid phthalates. (see the Environmental Working Group website for more information www.ewg.org).
  • Toss air freshening products and use essential oils instead.
  • Be careful of over-the-counter and prescription drugs because many lower fertility.
  • When replacing furniture or carpet, buy products without flame retardants or stain repellents.
  • Use a HEPA vacuum cleaner.
  • Avoid wrinkle-free and stain-resistant clothing.

And a special word of caution to young men: Avoid saunas and hot tubs which can lower your sperm count.


  1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6240172/