A major global health study has revealed a sharp rise in female infertility over the past three decades, with women aged 35 to 39 the most affected group. The findings, published in Scientific Reports, show that in 2021, over 110 million women worldwide were living with infertility—a jump of 84% since 1990.
1. What Is Female Infertility?
The World Health Organization (WHO) defines female infertility as the inability to become pregnant after 12 months of regular, unprotected sex. However, the researchers behind this new study used broader criteria. They classified infertility as either:
Primary infertility: no pregnancy after 5 years of unprotected sex.
Secondary infertility: no pregnancy 5 years after the last childbirth, despite not using contraception.
Infertility affects women around the globe. In the U.S., between 7% and 16% of women of reproductive age are affected. In developed countries, one in seven couples face infertility. In developing nations, that number climbs to one in four. In China alone, 15% of women of reproductive age are estimated to be infertile.
2. Why Is Infertility Rising?
There are many reasons why infertility is becoming more common. These include:
- Blocked fallopian tubes
- Ovulation issues
- Hormonal imbalances
- Genetic problems
- Environmental pollution
- Health conditions like endometriosis
Some of these causes, such as endometriosis, are also linked to other chronic conditions, including asthma and heart disease. Pollution and other environmental changes may even affect women at a genetic level, increasing the risk of infertility.
3. Cost of Treatment Is High
Treating infertility can be expensive. In the United States, one cycle of in-vitro fertilization (IVF) costs over $12,000. In Japan, it costs less than $4,000. These costs make treatment inaccessible for many women, especially in lower-income regions.
4. A Closer Look at the Study
Researchers used data from the Global Burden of Disease (GBD) study, which includes health statistics from 204 countries and territories. They looked at female infertility cases from 1990 to 2021, then made predictions through the year 2050.
The study focused on age-specific trends and regional differences. It also looked at disability-adjusted life years (DALYs), which measure the overall burden of a health condition. Because infertility isn’t fatal, the researchers measured only the years lived with disability (YLD).
Countries were grouped by their level of development using a tool called the Sociodemographic Index (SDI). The researchers used statistical models to forecast how infertility rates would change over time and looked for links between infertility and other factors, such as the Human Development Index (HDI).
5. Key Findings from 1990 to 2021
In 2021, around 110 million women were living with infertility.
The age-standardized prevalence rate (ASPR) was 1,367 cases per 100,000 women.
Over 601,000 DALYs were linked to infertility.
Women aged 35–39 were hit hardest, with rates 20% higher than in the 30–34 age group.
Middle-SDI regions had the highest number of cases.
High-middle-SDI regions had the highest ASPR.
Asia bore the greatest total burden, with China and India leading in numbers.
East Asia had the highest ASPR, while Australia and New Zealand had the lowest.
6. Regional and Temporal Trends
The study revealed stark differences based on region and development level:
Low and low-middle SDI regions: saw infertility rates fall at first, then sharply rise after 2010.
High SDI regions: experienced a slow increase, followed by a gradual decline.
When looking at SDI levels at a specific point in time:
- Countries with SDI under 0.50 saw stable or slightly decreasing rates.
- Countries with SDI between 0.50 and 0.75 saw moderate fluctuations.
- Countries with SDI over 0.75 showed significant decreases in infertility rates.
However, when measuring how infertility trends changed over time, countries with higher HDI scores tended to show increases in infertility rates up until HDI exceeded 0.8—after which the rate of increase began to slow.
7. Alarming Increase Among Women in Their 30s
The study noted a significant rise in infertility among women aged 30 to 34. This shift reflects trends such as later childbearing, increased urbanization, and more exposure to environmental pollutants. These factors are particularly common in fast-developing or industrialized nations.
8. Looking Ahead to 2050
Although the total number of infertility cases is expected to decline by 2050, the age-standardized prevalence rate (ASPR) and DALYs are projected to keep rising. This means:
More women will be affected relative to the size of their age group.
Aging populations and better diagnostic tools will drive up detection.
Lifestyle changes and pollution will continue to increase risk.
9. What This Means for Public Health
Infertility is more than a personal issue—it’s a public health concern that affects millions of women and couples globally. It can carry social stigma and psychological distress, particularly in cultures where childbearing is highly valued.
The study highlights the need for:
- Better infertility prevention and education
- Access to affordable treatment
- Policies that address environmental and lifestyle risks
Conclusion
Infertility now affects over 9% of women of reproductive age worldwide. Its burden has grown significantly since 1990 and continues to shift based on age, region, and socioeconomic status. Even though fewer total cases are expected by 2050, age-adjusted rates will continue to rise.
This global health challenge calls for urgent and targeted actions—especially in middle-SDI regions where the burden is rising fast. Awareness, early diagnosis, environmental protections, and access to care are essential to reverse this trend.
