In another example of racial and medical inequity, a sweeping systematic review of environmental studies reveals higher pregnancy risks associated with higher temperatures and pollution exposure. The mothers most at risk are black women.
The review, published in JAMA, looked at 57 environmental studies from 2007-present, and found a statistically significant connection between heat, air pollution, and poor or high-risk birth outcomes in the United States. The studies together covered more than 32 million births, and the stats aren’t positive.
Climate Change = Higher Temps
In general, higher temperatures are associated with more premature births, and climate change has exacerbated the intensity and frequency of heatwaves nationally. Low birth weight was also more common during high-heat conditions. Four of the studies surveyed tied sweltering heat to premature births, with increases ranging between 8.6-21%.
Rupa Basu, a study co-author and chief of the air and climate epidemiological section for the California Office of Environmental Health Hazard Assessment, told the New York Times that black Americans are less likely to have air conditioning or be able to afford the subsequent higher utility bills because of economic inequity. They also are more likely to live in urban areas with far fewer green belts to offset air pollution.
“We already know that these pregnancy outcomes are worse for black women,” said Basu. “It’s even more exacerbated by these exposures.”
Air Pollution Environmental Pregnancy Risk
Another factor for pregnancy risk is air pollution exposure. The review looked at two different types of pollution: ozone and fine particulate matter (PM 2.5). Both types are commonly found in urban areas.
Overall, the review noted that both types of air pollution were linked to preterm births, low birth weights, and stillbirths; one study found that exposure to high pollution levels in the last trimester linked to a 42% increased risk of stillbirth.
Living close to power plants was tied to a higher risk of preterm birth and birth weight. Even power plants that use garbage to produce energy caused more low birth weight risk the closer the mother lived to one.
These results were found nationally, with concentrations in California, Massachusetts, and Florida. As global temperatures rise, exacerbating already existing air pollution, the risks rise as well.
Asthma Makes the Risks Worse
The review found that asthma played a contributing risk factor, concluding that “women with asthma may be particularly susceptible to adverse outcomes, such as preterm birth and stillbirth, in association with PM2.5 exposure during gestation.”
Of course, one contributing factor to asthma is air pollution exposure. And, according to the Asthma and Allergy Foundation of America, women and African Americans are more likely to suffer from the condition. African Americans, particularly women, are three times more likely to die from asthma than any other group.
Experts note that air pollution regulations should be strengthened to address this problem, not weakened. And, while global warming is marching on, the issues of heat, pollution, and the necessary safety measures need to be addressed — especially for the highest risk group.
In the meantime, stop gap measures are the norm. “It’s not possible for everybody, but those that can should. If someone doesn’t have an air conditioner at home and is pregnant, the more time they can spend in air-conditioned places that have filtered air, the better for their pregnancy outcome,” Bruce Bekkar, a co-author of the study and a retired obstetrician told The Guardian.