Climate change raises concerns about Australians’ reproductive health
New research highlights potential risks to Australians’ reproductive health due to climate change, establishing a link between extreme bioclimatic exposure during pregnancy and birthweights for gestational age.
The large-scale study, conducted by Curtin University, examined more than 385,000 pregnancies in Western Australia from 2000 to 2015, spanning from 12 weeks before conception to birth.
Researchers investigated the correlation between low and high birthweights for gestational age and individuals’ exposure to outdoor heat or cold stress during pregnancy, measured using the Universal Thermal Climate Index (UTCI). The study aimed to assess the risks associated with being born too small or too large for gestational age.
The findings revealed that exposure to low and high biothermal stress during specific pregnancy periods was linked to an increased risk of babies being born smaller or larger for their gestational ages. The study defined an average biothermal exposure ranging between 8.1 and 30 degrees celsius, indicating slight cold stress and moderate heat stress on the UTCI scale.
Extreme biothermal exposures, specifically the 1st percentile (cold stress) and 99th percentile (heat stress), were found to be most associated with variations in birthweight for gestational age compared to median or no thermal stress.
Dr Sylvester Dodzi Nyadanu, the lead researcher, emphasised the significance of birth size, stating, “A baby’s size at birth is strongly associated with mortality risk during the first year, with developmental problems in childhood and the risk of various diseases in adulthood.”
The study identified subpopulations at a higher risk of abnormal fetal growth due to biothermal stress, including non-Caucasian individuals, male births, pregnancies in those aged 35 and above, those in rural areas, and those who smoked during pregnancy.
Dr Nyadanu underlined the broader implications of the study, stating, “Our research adds to the growing collection of observational studies reporting on maternal exposure to ambient temperature and pregnancy outcomes such as pregnancy complications, preterm birth, stillbirth, and low birth weight.”
The study reinforces the growing concerns about the adverse impacts of climate changes on people’s health, including reproductive health, and highlights the potential threats posed by heatwaves, cold spells, vector-borne diseases, natural disasters, and food and water insecurity.
Dr Nyadanu emphasised the need for climate care interventions as part of reproductive healthcare during the vulnerable period of pregnancy.
The study, titled Critical windows of maternal exposure to biothermal stress and birth weight for gestational age in Western Australia, was published in Environmental Health Perspectives.