Impact of heat waves on semen quality: A retrospective study in Argentina between 2005 and 2023

Abstract

Heat waves (HW; periods with daily temperatures surpassing the historical average for a specific region) have become more frequent worldwide in recent years, but few studies have reported their association with semen quality. The study by Verón et al. evaluated data from 54 926 men (18-60 years) undergoing routine semen analysis between 2005- 2023 at CEUSA-LAEH andrology unit, in Buenos Aires, Argentina. Temperature readings were provided by the Servicio Meteorológico Nacional. A total of 124 days had HW (at least 3 consecutive days with over 22°C (minimum) and 32.3°C (maximum) for Buenos Aires). Men exposed to HW during spermatogenesis exhibited lower sperm number (concentration and count; P<0.0001) and normal morphology (% normal sperm and normal motile count; P<0.05). These differences were most pronounced between semen samples from years with several HW (2013/ 2023) and none (2005/2007/2016). A multiple regression analysis revealed a negative association between semen quality and HW length, suggesting a prolonged exposure more detrimental than an acute one. Exposure to ≥6-days HW during spermatogenesis resulted in a negative (P<0.05) association between early exposure (spermatocytogenesis: 64- 90 days prior semen collection) and semen quality. This study highlights the negative association between early exposure to HW during sperm development, as evidenced by a decrease in seminal quality. These results contribute to the management of patients in fertility consultation, as well as to having a comprehensive collaborative approach that involves global government policies, sustainable practices and coordinated efforts between policies, medical care and scientific research.