Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Residential proximity to bushfire events in Australia impaired subsequent human oocyte in vitro fertilization rates (#209)

Amy Winship 1 , Kelli Sorby 2 , Anna Tran 2 , Meaghan Griffiths 1 , Lauren Alesi 1 , Teharn Hegarty 1 , Mark Green 3 , Karla Hutt 1
  1. Department of Anatomy & Developmental Biology, Monash University, Clayton, VIC , Australia
  2. Number One Fertility, Melbourne
  3. University of Melbourne, Melbourne

Climate change is currently the greatest threat facing human health, worldwide. The global incidence and severity of bushfires is increasing, particularly in Australia, causing growing risks of smoke inhalation. While there are overlaps in the chemical makeup between bushfire, industrial or cigarette smoke, notably, bushfires can release unique compounds. Defining the specific impacts of bushfire smoke exposure on reproductive function has important consequences for population size and health; essential inputs to model the potential future health burdens associated with climate change.

 

The aims of this retrospective cohort study were to examine the association between human oocyte retrieval rates with residential proximity to largescale Victorian fire events during the Australian ‘Black Summer’ bushfires of 2019-2020, compared with women from distal areas to fire events. All data was stratified based on oocyte retrieval either before, or after the bushfires from December 2019 – January 2020.

 

Residing from postcodes proximal to bushfire zones was associated with a significant 18.8-23.4% reduction in the proportion of oocytes fertilized from all mature oocytes retrieved (mean 34.8%; 95% confidence interval [CI], 22.5, 47.0) versus all other groups. Rates of blastocysts from mature oocytes retrieved was significantly reduced by 8.8% in women from exposure areas post-fires (mean 13.3% [CI] 7.3%, 19.2%), compared to non-exposure areas post-fires (mean 22.1% [CI] 21.0%, 23.2%). Notably, while there were two clinical pregnancies of the cycles in women from exposure areas post-fires, this was the only group to record no live births. This association between smoke exposure and oocyte retrieval may be an important factor to consider in future research.

 

Exposure to bushfire smoke was associated with reduced retrieval of quality oocytes that successfully underwent fertilization. These results raise concern that increasing incidence and severity of bushfire events worldwide may result in accelerated reproductive aging among women.