John Metcalfe is CityLab’s Bay Area bureau chief, based in Oakland. His coverage focuses on climate change and the science of cities.
Researchers believe less rain and more hot days are affecting pregnant women.
There’s ample evidence climate change will likely affect our children’s health—breeding stagnant, lung-punishing air, for instance, and possibly doubling the pollen count by 2040. But is it possible the warming world will hurt newborns before they even have a chance to live in it?
Researchers at the University of Utah and elsewhere say that could be so. They’ve analyzed 70,000 births in Africa from 1986 to 2010 and found that climate change could be lowering birth weights. Specifically, they believe women in places with declining rainfall and an increase in hot days are having more underweight babies (defined as those below 5.5 pounds).
Kathryn Grace, an assistant geography professor at Utah, and colleagues studied USAID-funded health data and weather records for 19 Africa countries. They were able to calculate regional precipitation amounts and temperatures near each woman throughout her pregnancy. Areas that experienced more 100-plus-degree days also had smaller babies, they say. Even a single day in the second trimester with the mercury topping 100 correlated to a 0.9-gram weight deficit, according to their study in Global Environmental Change.
Though this investigation focused on Africa, Grace says she sees “potential for similar outcomes everywhere,” according to a Utah press release. Here’s more from the university on why that’s important:
With the inaccuracy of determining exactly when a pregnancy began in rural countries which lack pregnancy tests and the inability to measure characteristics like a newborn's cognitive development, low birth weight is the most reliable measure of whether a pregnancy has been negatively affected by an external factor….
Low birth weight infants are more susceptible to illness, face a higher risk of mortality, are more likely to develop disabilities and are less likely to attain the same level of education and income as an infant born within a healthy weight range.
Consequently, the financial burden of a low birth weight infant can be significant. The costs of newborn intensive care unit stays and services, re-hospitalization and long-term morbidity can add up quickly, and in developing countries where such support services are less common and physical disability is considered a social stigma, low birth weight can be particularly impactful.