Epidemiological characteristics of infertility, 1990-2021, and 15-year forecasts: an analysis based on the global burden of disease study 2021.

Background: Infertility, defined as the inability to achieve pregnancy after 1 year of regular unprotected intercourse, affects approximately 186 million people globally, with consistent prevalence across different income levels. Globally, the rising infertility rates are impacting population growth and individual quality of life. Infertility is not just a personal issue but also a public health concern, with social and economic implications, including stigmatization, marital discord, and mental strain. The COVID-19 pandemic has further exacerbated mental health issues among individuals with infertility, underscoring the need for research into the mental health impacts and access to fertility services. Economically, infertility poses a significant financial burden, especially in regions where Assisted Reproductive Technology (ART) costs can be up to 200% of the GDP per capita. Understanding the complexities and spread of infertility is essential for guiding policy decisions and program rollouts, with studies analyzing infertility issues based on the Global Burden of Disease (GBD) database.

Methods: The study leverages data from the GBD 2021, encompassing 371 conditions or injuries and 88 risk factors across 204 nations. It examines prevalence, disability-adjusted life years (DALYs), age-standardized prevalence rate (ASPR), and age-standardized DALYs rate (ASDR) for infertility, categorized by sex, age, regions, and nations. The Social and Demographic Index (SDI), reflecting socio-economic levels, is used to analyze its correlation with infertility burden. The study employs decomposition analysis and frontier analysis methods to assess changes in infertility prevalence and DALYs, and Spearman's rank correlation coefficient to confirm relationships between age-standardized rates (ASRs) and SDI. The estimated annual percentage change (EAPC) of rates, with 95% confidence intervals (CIs), was calculated.

Results: In 2021, it was calculated that the global ASPR for male infertility stood at 1354.76 cases per 100,000 individuals, with a 95% Uncertainty Interval ranging from 802.12 to 2174.77 cases per 100,000 individuals. For female infertility, the ASPR was recorded at 2764.62 per 100,000 individuals (95% UI: 1476.33-4862.57 per 100,000 individuals). Between 1990 and 2021, the EAPC in ASPR was observed to be 0.5% (95% CI 0.36-0.64) for males and 0.7% (95% CI 0.53-0.87) for females. In that same year, the global ASDR attributed to male infertility was 7.84 per 100,000 individuals (95% UI: 2.85-18.56 per 100,000 individuals), while for female infertility, it amounted to 15.12 per 100,000 individuals (95% UI: 5.35-36.88 per 100,000 individuals). The EAPC for ASDR linked to male and female infertility from 1990 to 2021 was assessed at 0.51% (95% CI 0.38-0.65) and 0.71% (95% CI 0.54-0.88), respectively. Among the 204 countries and territories in 2021, India ranked first in both the prevalence of cases and DALYs associated with male and female infertility, followed by China and Indonesia. Additionally, the investigation revealed a slight negative correlation between the ASPR and ASDR of infertility and the SDI. Decomposition analysis indicated that approximately 65% of the rise in the global burden of infertility could be attributed to population growth. Frontier analysis suggested that the variations in efficiency frontiers across specific SDI levels diminish as the SDI increases. Looking forward, the study projects a global rise in ASPR and ASDR for infertility between 2022 and 2036.

Conclusions: The worldwide prevalence of infertility has substantially increased between 1990 and 2021, largely as a result of population growth. This trend highlights the pressing necessity for better strategies concerning prevention, diagnosis, and treatment, particularly in low and middle-income nations. Strengthening healthcare infrastructures, enhancing access to high-quality medical services, and raising awareness about infertility are vital measures to tackle this issue. The results of the study offer essential information to help policymakers and health officials formulate targeted strategies for the prevention and management of infertility.