Wildfire Smoke Exposure is Associated with Decreased Sperm Concentration and Total Motile Sperm Count

Area of Science:

• Environmental Health
• Reproductive Biology
• Epidemiology

Background:

• Increasing prevalence of wildfires necessitates evaluating their impact on human fertility.
• Previous research suggests potential links between environmental exposures and reproductive health outcomes.

Purpose of the Study:

• To investigate the association between wildfire smoke exposure and semen analysis parameters in patients undergoing intrauterine insemination (IUI).
• To hypothesize that wildfire smoke exposure leads to a decrease in total motile sperm count.

Main Methods:

• Retrospective cohort study design.
• Analysis of semen samples from 84 patients undergoing IUI at the University of Washington between 2018-2022.
• Paired pre-exposure and post-exposure semen analysis to assess changes during wildfire smoke events in 2018, 2020, and 2022.

Main Results:

• Observed significant declines in sperm concentration, total sperm count, total motile sperm count, and total progressively motile sperm count.
• A notable increase in the percentage of progressively motile sperm was also recorded.
• These trends remained consistent across different wildfire event years.

Conclusions:

• Findings support previous studies indicating that wildfire smoke exposure adversely affects sperm quality.
• Highlights the need for continued research into the effects of wildfire smoke on male fertility and assisted reproductive technologies.
• Emphasizes the growing concern for reproductive health in the context of climate change and increasing smoke exposure.