Women around the world, on average, now have fewer children than previous generations.
The trend, driven by greater access to education and contraception, more women taking jobs and changing attitudes toward having children, is expected to see the populations of dozens of countries shrink by 2100.
Dr Jennifer Sciubba, author of 8 Billion and Counting: How Sex, Death and Migration Shape Our World, told MailOnline that people are choosing to have smaller families and the change “is permanent”.
“That’s why it’s wise to focus on working within this new reality rather than trying to change it,” he said.
Sexual education and contraception.
Increasing education and access to contraceptives is one of the reasons behind the falling global fertility rate.
Education about pregnancy and contraception has increased: sex education classes began in the US in the 1970s and became mandatory in the UK in the 1990s.
“There’s an old saying that ‘education is the best contraceptive’ and I think that’s relevant” to explaining declining birth rates, said Professor Allan Pacey, an andrologist at the University of Sheffield and former president of the Society. British Fertility.
Elina Pradhan, a health specialist at the World Bank, suggests that more educated women choose to have fewer children because of concerns about earning less when they take time off before and after giving birth.
In the UK, three in 10 mothers and one in 20 fathers say they have had to reduce their working hours due to caring for their children, according to ONS data.
They may also be more exposed to different ideas about family size through school and the connections they make during their education, which encourages them to think more critically about the number of children they want, she said.
And more educated women may know more about prenatal care and child health and have more access to medical care, Pradhan added.
Professor Jonathan Portes, an economist at King’s College London, said women’s greater control over their own fertility means that “households, and women in particular, want fewer children and are able to do so.”
More women enter the workplace
There are more women in the workplace now than 50 years ago (72 vs. 52 percent), which has contributed to the global fertility rate halving over the same period.
Professor Portes also noted that the drop in the birth rate may also be due to the structure of the labor and housing markets, expensive childcare and gender roles that make it difficult for many women to combine their career aspirations with having a family. .
The UK Government has “implemented the most anti-family policies of any government in living memory” by cutting services that support families, along with benefit cuts that “deliberately punish low-income families with children”, he added.
As more women have entered the workforce, the age at which they must start a family has been pushed back. ONS data shows that the most common age for a woman born in 1949 to give birth was 22. But women born in 1975 were more likely to have children when they were 31 years old.
In another sign that later childbearing is on the rise, half of women born in 1990, the most recent cohort to reach age 30, remained childless by age 30, the highest rate on record.
Women repeatedly cite work-related reasons for postponing having children, and surveys reveal that most women want to move up the career ladder before conceiving.
However, the measure could lead to women having fewer children than they planned. In the 1990s, only 6,700 IVF cycles, a technique to help people with fertility problems, have a baby, were carried out annually in the UK. But this number soared to more than 69,000 in 2019, suggesting that more women are struggling to conceive naturally.
Decreased sperm count
Reproductive experts have also raised the alarm that biological factors, such as declining sperm counts and changes in sexual development, could “threaten human survival.”
Dr. Shanna Swan, an epidemiologist at the Icahn School of Medicine at Mount Sinai in New York City, authored a groundbreaking 2017 study that revealed that global sperm counts have dropped by more than half in recent years. four decades.
He warned that the culprits are “chemicals that are everywhere,” such as phthalates found in toiletries, food packaging and children’s toys. The chemicals cause a hormonal imbalance that can cause “reproductive havoc,” she said.
Factors such as tobacco and marijuana smoking and rising obesity rates may also play a role, Dr. Swan said.
Studies have also noted that air pollution reduces fertility rates, suggesting that it triggers inflammation that can harm egg and sperm production.
However, Professor Pacey, an expert in fertility and sperm quality, said: “I really don’t think that any change in sperm quality is responsible for the decline in birth rates.”
“In fact, I don’t believe the current evidence that sperm quality has decreased.”
He said: ‘I think a much bigger problem with falling birth rates is the fact that: (a) people are choosing to have fewer children; and (b) they are waiting until they are older to have them.’
Fears of bringing children into the world
Some scientists consider choosing not to have children to be the best thing a person can do for the planet, compared to reducing energy use, traveling, and choosing foods based on their carbon footprint.
Scientists at Oregon State University estimated that each child adds about 9,441 metric tons of carbon dioxide to a woman’s “carbon legacy.” Each metric ton is equivalent to going around the circumference of the world.
Experts say the data is discouraging climate-conscious people from having babies, while others are choosing not to have children due to worldwide fears that they will grow up.
Dr Britt Wray, a human and planetary health fellow at Stanford University, said the drop in fertility rates was due to “fear of a degraded future due to climate change”.
She was one of the authors of a Lancet study of 10,000 volunteers, which revealed that four in ten young people fear bringing children into the world due to climate concerns.
Professor David Coleman, emeritus professor of demography at the University of Oxford, told MailOnline that people’s decision not to have children is “understandable” due to poor conditions such as climate change.