Age Disparity in Couples Seeking First Medical Help for Infertility Has Changed Over the Last Twenty Years: A Socio-Demographic Analysis

Purpose: Epidemiological studies have suggested that men are usually coupled with younger women. Parental age at first child have steadily increased over last decades. Accordingly, the age gap within partners has changed in the real-life setting over the same time frame. To analyze differences in partners' age (delta [Delta] age [M-F]) over a 20-year time frame among 1,605 men and their partners, seeking medical help for primary couple's infertility at a single center (2005-2024). Materials and Methods: Partners' age was recorded, Delta age was calculated. Comorbidities were scored with Charlson Comorbidity Index (CCI). Educational status was recorded. Sexual dysfunctions were self-reported for all male patients. Descriptive statistics and linear regression analyses were applied. Results: Median (interquartile range) patient's and partner's age were 37 (34-41) and 34 (31-37) years. Median Delta age was 3 (0-6) years. Delta age decreased by 1 point for each decade, being similar between 2005-2010 and 2011-2015, then decreasing from 2016-2020 to 2011-2015 and from 2021-2024 to 2011-2015 (all p<0.01). Similar values were found between 2021-2024 and 2016-2020, suggesting 2015 as a cutoff after which Delta age decreased compared to earlier years, thus remaining afterwards stable. Delta age change was related to increasing age bands of the female partner since male age was similar across the time frame. Men with low education status, with CCI >= 1 and with sedentary lifestyle had higher Delta age (all p<0.01). Infertile men who self-reported erectile dysfunction had higher Delta age than those with normal erectile function (p=0.01). Conclusions: In infertile couples, age-difference relationships decreased over time due to female ageing at first parenthood. Greater Delta age was linked to lower education, higher comorbidities, and a sedentary lifestyle in male partners. Erectile dysfunction was more common in couples with higher Delta age.