The number of women worldwide seeking medical help for fertility problems is growing, with a predominantly Chinese research team calculating that cases could rise from around 54 million to 80 million by 2036.
Many women are choosing to have children at a significantly older age than in previous generations and then finding that age-related infertility prevents them from becoming pregnant, the team said in The Lancet Obstetrics, Gynaecology, & Women's Health in July.
Wealthier countries, where women have children later on average, are particularly affected, the study said. Around 8% to 12% of couples worldwide have fertility problems, it added.
Women aged between 35 and 49 are especially affected. In this group, infertility diagnoses increased sharply worldwide between 1990 and 2023 – from around 27 million to almost 54 million, the research group wrote.
"People are having children at an older age due to longer periods of study, economic uncertainty and youth unemployment," said Eva Beaujouan of the University of Vienna. She added that in younger years, priority is given to other activities such as career or travel.
Factors such as longer life expectancy and shifts in values and attitudes also play a role, said Beaujouan, a professor of demography who was not herself involved in the study.
The trend probably cannot be reversed – but it may be possible to stabilise it. States need to invest sufficiently in reliable childcare and supportive infrastructure, "so that every person who wants to have children can do so at the age they choose," she said.
From the age of 35, egg reserves and egg quality decline significantly, said Beda Hartmann of the Sigmund Freud Private University in Vienna. As a result, the likelihood of pregnancy decreases.
Hartmann expects interest in so-called social egg freezing to increase in the coming years.
This refers to the preventive freezing of unfertilised eggs for a possible pregnancy at a later point in time.
"The success of a pregnancy depends significantly on the age of the egg," he said. He recommended freezing eggs from the age of 25.
For the study, the team led by Yuanyuan Du of Chongqing University Hospital evaluated data from 204 countries and regions covering the period 1990 to 2023, drawing on searches of specialist literature and databases.
However, Beaujouan cautioned that it is difficult to assess how precise the published figures actually are, because the methodology – and in particular the extrapolation – is not described in sufficient detail. She said she had doubts about the data from Austria in particular, which appeared far too high. – dpa
