New research published in The Lancet Obstetrics, Gynaecology, & Women’s Health has shed light on the escalating global prevalence of infertility among older women, specifically those aged 35 to 49. The study, which draws on the extensive Global Burden of Disease (GBD 2023) database, suggests a substantial rise in affected women, with projections indicating a global figure of nearly 79.6 million by 2036, up from an estimated 53.6 million in 2023.
Professor Guillermo Antiñolo Gil, an expert in Obstetrics and Gynaecology at the University of Seville, commented on the study's methodology, deeming it reliable. He noted that its primary contribution is its focus on the 35-49 age group, where the biological decline in fertility becomes more pronounced. However, Professor Antiñolo Gil urged caution in interpreting the figures, explaining that the GBD's infertility prevalence is a modelled figure that encompasses more than just biological factors. It also reflects a woman's desire to have children, her pursuit of medical care, and her access to diagnostic services, rather than solely measuring biological infertility.
He further clarified that the study calculates infertility based on all women aged 35 to 49, not exclusively those actively attempting to conceive, which is the standard clinical definition. Consequently, an increase in the number of women seeking pregnancy later in life could inflate the rate, even if the biological risk per attempt remains unchanged. This nuance suggests that the observed increase should not be solely interpreted as a rise in biological infertility risk.
The research also highlights a notable shift in the relative burden of infertility, moving from less developed nations towards higher-income countries. This trend underscores the influence of socio-economic factors. Professor Antiñolo Gil pointed to Spain's situation, where delayed motherhood due to financial constraints, difficulties in balancing work and family life, and career concerns are significant contributors, rather than a new biological epidemic.
He advocated for a social and preventative approach to address this challenge. Key measures include providing early information on age-related fertility decline, implementing policies to tackle structural causes of delayed childbearing such as housing and job insecurity, improving work-life balance, and promoting shared parental responsibilities. Additionally, he suggested early reproductive assessments in primary care and transparent advice on egg freezing, without presenting it as a guaranteed solution. The importance of considering the male factor, which accounts for a significant proportion of infertility cases but was excluded from this study, was also emphasised.