Chinese research maps the evolving global burden of infertility

Infertility is a significant global health challenge impacting millions of families worldwide. Utilizing data from the Global Burden of Disease (GBD) 2021 study, a Chinese-led study examined global, regional, and national infertility prevalence and years lived with disability (YLDs) from 1990 to 2021. The study revealed a sustained increase in the global burden of infertility over the three decades, with a higher and more rapidly growing burden among women, alongside notable regional disparities. These findings could serve as a critical evidence base for developing evidence-based policies and resource allocation strategies to address the infertility burden.

Infertility, clinically defined as the inability to achieve pregnancy after at least 1 year of regular unprotected sexual intercourse, not only contributes to reducing birth rates but also impairs couples’ quality of life, elevates the risk of chronic diseases, and may lead to psychological distress and broader social consequences. A comprehensive understanding of the current status and trends in the burden of infertility is essential for guiding policy development. To address this need, a research team led by Professor Zhibin Hu from Nanjing Medical University performed an in-depth analysis, the findings of which have been published in Chinese Medical Journal.

In 2021, approximately 198 million individuals were affected by infertility worldwide. This total comprised 143.26 million (95% uncertainty interval [UI]: 91.40–228.21 million) women, which reflects an 82% increase since 1990, and 55.48 million (95% UI: 33.09–89.19 million) men, representing a 74% rise over the same period. Key burden indicators, such as YLDs, showed a concurrent upward trend. Globally in 2021, YLDs linked to female infertility reached 801,995 (95% UI: 312,683–1,904,064), marking an 82% increase since 1990. Similarly, YLDs from male infertility totaled 325,681 (95% UI: 118,921–775,247), up 74% over the same period.

From 1990 to 2021, the global age-standardized prevalence rate (ASPR) and age-standardized YLDs rate (ASYR) for female infertility increased annually by an average of 0.59% (95% confidence interval [CI]: 0.45–0.72%), compared to 0.50% (95% CI: 0.36–0.63%) for male. The year 2010 marked a critical turning point, after which the infertility burden rose rapidly following a period of relative stability across most regions. A substantial sex difference persisted, with female cases in 2021 being about 2.6 times more numerous than male cases. This disparity may be attributable to the broader range of etiological factors in female infertility, including diminished ovarian reserve and polycystic ovary syndrome, combined with sociocultural factors that lead to higher detection rates in women and underdiagnoses in men. The burden of infertility also varied markedly by age. Women aged 35–39 bore the highest burden, with the prevalence rate of 13,684 per 100,000 and YLDs of 74 per 100,000 in 2021. The corresponding figures for men were 4,722 per 100,000 and 26 per 100,000, respectively. Later marriage and childbearing, along with unhealthy lifestyles, likely contributed to the elevated infertility burden in this age group.

Furthermore, the burden of infertility demonstrates a horizontal S-shaped relationship with socioeconomic development, as measured by the sociodemographic index (SDI). In less developed regions (SDI below 0.5), the burden of infertility declines. However, as development progresses into the middle range (SDI between 0.5 and 0.7), this burden increases. The trend reverses once more in highly developed regions (SDI above 0.7), where the burden begins to fall again.

China’s infertility profile and its recent positive developments merit attention. The 2021 data indicate 33.8 million (95% UI: 19.13–56.47 million) female cases, representing 23.59% of the global female total, and 11.91 million (95% UI: 6.54–20.82 million) male cases, representing 21.47% of the global male cases. Notably, compared with 2019, China recorded reductions of 699,000 female cases and 155,000 male cases by 2021. This favorable trend may be attributed to enhanced national reproductive health education and improved accessibility to treatment technologies.

Reference

DOI: https://doi.org/10.1097/cm9.0000000000003838

About Professor Zhibin Hu from Nanjing Medical University

Prof. Zhibin Hu is a Professor of Epidemiology, Doctoral Supervisor, President of Nanjing Medical University and the Director of the State Key Laboratory of Reproductive Medicine and Offspring Health at Nanjing Medical University. At the same time, Prof. Hu is a recipient of the National Distinguished Young Scholar Award, a Chang Jiang Scholars Program Distinguished Professor by the Ministry of Education, a Leading Talent in Science and Technology Innovation for Young and Middle-Aged Researchers by the Ministry of Science and Technology, and a distinguished expert in the National “Hundred, Thousand, Ten Thousand Program” and the National Talent Program for Experts with Outstanding Contributions. Prof. Hu has been dedicated to the research of molecular and genetic epidemiology of complex diseases. He has published more than 300 research papers in renowned international journals, including Nat Genet, Nat Med, Cell Res, J Clin Oncol, and J Clin Invest. He has been continuously selected as an Elsevier Highly Cited Scholar in China from 2014 to 2024.

About Associate Professor Qiufen Sun from Nanjing Medical University

Dr. Qiufen Sun, PhD., Associate Professor at the School of Public Health, Nanjing Medical University, specializes in chronic disease epidemiology. Her research findings have been published in high-impact journals including Lancet Public Health, Nature Human Behaviour, and Lancet Regional Health-Western Pacific.

About Mr. Rui Lin from Nanjing Medical University

Mr. Rui Lin, a PhD candidate at the School of Public Health, Southeast University, specializes in reproductive and offspring health. He published two research papers in Expert Review of Vaccines and Chinese Journal of Preventive Medicine.

Funding information

This work was supported by grants from the China National Key Research & Development (R&D) Plan (No. 2021YFC2700600) and the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 82221005).