Overview

• The peer-reviewed study in Fertility and Sterility analyzed semen from 84 men undergoing intrauterine insemination from 2018 to 2022 in the Seattle region.
• Researchers compared samples collected before versus during major wildfire smoke periods and observed declines in concentration and multiple sperm-count measures during exposure.
• The percentage of progressively motile sperm rose slightly, yet overall sperm quality indicators fell.
• Participants served as their own controls, with consistent results across the 2018, 2020, and 2022 smoke events.
• The study reported pregnancy and live birth rates of 11% and 9% in this clinic cohort, and the team has launched a prospective pilot to assess timing, recovery, and implications for conception.