Heat, Pollution Put Black Mothers at Greater Risk of Poor Birth Outcomes

A sweeping review of birth outcomes in the U.S. since the early 2000s has found that exposure to extreme heat and air pollution during pregnancy brings increased risk of delivering pre-term, low weight, or stillborn babies. And Black mothers are suffering more from these effects than white mothers.

The review “presents some of the most sweeping evidence so far linking aspects of climate change with harm to newborn children,” reports the New York Times. The report, published last week in JAMA Network Open, collated data from nearly 60 studies published since 2007, covering more than 32 million births.  

“Black moms matter. It’s time to really be paying attention to the groups that are especially vulnerable,” said co-author Bruce Bekkar, a San Diego–based climate activist and retired obstetrician. 

The data revealed that Black American mothers and their babies are far less likely than their white counterparts to enjoy a healthy birth—because they are far more likely to live in hot and polluted communities. According to a 2018 paper included in the review, “Black mothers are 2.4 times more likely to have children with low birth weight than white women.” The Times also flags an international analysis in 2019 which found that “the risk of stillbirth was as much as twice as great for Black mothers as for whites” across several wealthy nations.

The Times describes a clear correlation between high temperatures and premature birth, with four studies finding that maternal exposure to extreme summer heat increased the risk of premature babies between 8.6 and 21%. Another study found that “every temperature increase of 1°C in the week before delivery corresponded with a 6% greater likelihood of stillbirth between May and September.”

Air pollution proved an even stronger determinant, with “the vast majority of the studies reviewed in the paper conclud[ing] that ozone and PM2.5 are also associated with pre-term births, low birth weights, and stillbirths.”

In one study, “high exposure to air pollution during the final trimester of pregnancy was linked to a 42% increase in the risk of stillbirth,” while another, which looked at nearly 500,000 Florida births between 2004 and 2005, found a clear correlation between maternal proximity to power plants that use garbage as an energy and low birth weight.

Another finding of the review: “Severe pre-term birth, defined as a birth that occurs fewer than 28 weeks into pregnancy, increased by 52% for asthmatic mothers exposed to high levels of air pollution.”

Black neighbourhoods in the U.S. are more likely than white ones to be located near power plants and other s of air pollution, said Rupa Basu, another co-author of the report and chief of the air and climate epidemiological section for the Office of Environmental Health Hazard Assessment in California. Black neighbourhoods are also likely to be far from the green spaces that help keep summer heat in check. And many mothers in poorer areas lack air conditioning, and have little access to medical care.

Basu also warned of the existence of a “colour bar” in treatment: an expectant mother’s skin colour might well affect the quality of the care she receives throughout her pregnancy.

The JAMA review is “a moment of reckoning for racial injustice and health disparities,” said Catherine Garcia Flowers, a member of the Houston for Moms Clean Air Force.  

“Doing nothing about air pollution, which so clearly has a greater impact on Black Americans, is racism in action,” she said.