Trends of male factor causes of couples’ infertility over time have been poorly investigated.
We investigated trends in the causes of pure male factor infertility (MFI) throughout the last ten years in a tertiary-referral academic andrology centre.
Baseline characteristics at first presentation from a cohort of 1647 consecutive MFI patients belonging to primary infertile couples between 2008 and 2018 have been comprehensively collected over time. Seven major causes of MFI were identified: varicocele; history of cryptorchidism; hypogonadism (primary and secondary); obstructive azoospermia; genetic abnormalities; other causes (large group including the remnant conditions of known causes); and, idiopathic infertility. Rates of different MFI causes over the study period were analysed. Multivariable logistic regression models tested the likelihood of MFI causes over time. Estimated trends were explored graphically.
Of all, varicocele was found in 615 (37.3%), cryptorchidism in 124 (7.5%), genetic abnormalities in 61 (3.7%), hypogonadism in 165 (10%), obstructive conditions in 55 (3.3%), other causes in 129 (7.8%) patients, and idiopathic infertility in 498 (30.3%) patients, respectively. Over time, a reduction in the proportions of cryptorchidism and varicocele (all p<0.001) cases was observed, along with an increase in the proportions of hypogonadism, other causes of MFI and idiopathic cases (all p≤0.01). Rates of genetic and obstructive cases remained stable. The observed trends were confirmed at logistic regression models.
A decreasing trend in the proportions of varicocele and cryptorchidism at first presentation was observed over the last ten years; conversely, the proportions of idiopathic cases, hypogonadal patients and infertile men presenting with other MFI causes significantly increased over the same time frame at a single tertiary-referral academic andrology centre.

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