Low births: Why there may be no babies born by 2070

America has revived the conversation around declining fertility rates after releasing a record low in births.

US government data last week showed that the country had reported the largest single-year drop in birth rates in nearly 50 years among women across all age groups, major races and ethnic groups.

This decline mirrors global birth rates, as women postpone motherhood and opt for smaller families as the costs of living rises.

The boost in women’s empowerment has also led to an increase in the number of those educated, finding employment, and getting more economic independence, which has boosted the options available to them beyond motherhood.

The latest Kenya Demographic and Health Survey (KDHS) shows that the average age at first birth for a woman who only has a primary education is 18, while a woman who has completed secondary school will have her first child at 23.

Education is a factor for men too, with the data showing those who had completed secondary education on average first become fathers at 26.

Increased availability and access to contraception has also contributed to lower birth rates, as has a decrease in infant mortality rate occasioned by better healthcare. Researchers are now adding another factor to the equation – falling sperm counts as a result of changes in the environment.

In her 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, environmental and reproductive epidemiologist Shanna Swan blames “everywhere chemicals” for falling fertility rates.

Products like phthalates and Bisphenol-A (commonly known as BPA, and found in plastics and cosmetics like shaving creams and pesticides) affect endocrines, she says.

This has led to falling testosterone levels, more genital abnormalities among boys, earlier puberty for girls and growing rates of testicular cancer and erectile dysfunction.

This, Swan says, has translated into a 1 per cent increase per year in adverse reproductive changes for men. Additionally, disruptions in hormonal balance brought on by smoking and obesity have caused “various degrees of reproductive havoc, threatening human survival.”

Closer home, Kenya’s fertility rate has dropped by nearly half.

Between 1970 and 2020, Kenya’s total fertility rate fell from 8.1 births per woman to 3.5, which is just a baby shy of 2.1, the population replacement level.

This is the average number of children per woman needed for each generation to exactly replace itself without needing international immigration.

 World’s population

Studies have found that almost half the world’s population - 83 countries in total - have fertility rates below 2.1, with South Korea at the lead with a fertility rate of 0.98.

By 2050, more than 130 countries, or about two-thirds of the world’s population, are projected to have fertility rates below replacement level

If you look at the curve on sperm count and project it forward - which is, however, risky - it reaches zero in 2045 in the USA (and in 2070 in Kenya).

This means the median man would have essentially no viable sperm by then. Swan puts these data in rather bleak terms: “humans could become an endangered species”.

So how can humankind safeguard its fertility?

Swan says we need to protect ourselves from damaging chemicals, which is easier said than done.