A new analysis of global health data reveals that 53.6 million women aged 35 to 49 are currently unable to conceive, signaling a deepening worldwide fertility crisis. The study, which examined health records from 204 countries between 1990 and 2023, found a steady increase in the infertility burden within this age group.
The research, published in The Lancet Obstetrics, Gynaecology, & Women's Health, reported that the infertility rate per 100,000 women aged 35-49 rose from approximately 6,001 in 1990 to 6,907 in 2023. While women up to age 49 are sometimes included in reproductive statistics, fertility typically declines sharply from the mid-30s and is significantly low by the late 40s. The study defined infertility as the inability to achieve a clinical pregnancy after 12 months of regular, unprotected intercourse.
Researchers observed the fastest projected rise in infertility among women aged 35 to 39. This trend, the study suggests, reflects a broader societal shift where women are increasingly delaying childbirth into their late thirties due to pursuits in education and career advancement. By the time they are ready to start a family, their fertility may have already diminished.
In the United Kingdom, for example, the average age of mothers giving birth in England and Wales reached a record 30.9 years in 2021, a steady increase from 26.4 years in 1973. Concurrently, births among women over 40 have more than doubled compared to teenage mothers, a reversal from fifty years ago when teenage mothers were nine times more common than those over 40.
The study's authors, including lead author Yuanyuan Du, point to several contributing factors beyond delayed childbearing. Obesity and stress are identified as potential influences on fertility. Additionally, increased access to fertility treatments may have led to a rise in both the number of women seeking help and the diagnosis of infertility cases. The authors noted a correlation between economic instability, such as the global financial crisis around 2006-2010, and a temporary dip in observed infertility, which they suggest might be linked to economic barriers affecting diagnosis rather than a true reduction in prevalence.
The rise in infertility is not confined to lower-income countries. The data indicates a shift towards higher-income and more developed nations, likely due to later motherhood, population aging, and changing reproductive patterns. However, women in less affluent regions continue to face significant challenges in accessing fertility testing and treatment.
Regionally, East Asia showed the highest burden of infertility in 2023, while Australasia had the lowest. At the country level, the Central African Republic reported the highest burden, with Nepal reporting the lowest.
The consequences of infertility extend beyond the individual, encompassing psychological, social, and economic impacts such as distress, stigma, financial strain, and relationship difficulties. The researchers advocate for fertility care to be prioritized as a public health issue, emphasizing the need for better early detection, expanded access to services, and policies adapted to varying national resources and needs. They project that if current trends continue, the total number of women affected by infertility could reach 79.6 million by 2036.