While many of the future (and current) effects of climate change are rather intuitive -- rising sea levels, rising temperatures, increasing storminess, etc -- others are not. This is a point brought home by new research from the University of Utah -- research which has found that climate change will likely lead to lower birth weights throughout much of the world.
The findings are the result of an analysis of the relationship between pregnant women's exposure to very hot days (and low precipitation) and fetal development. The analysis utilized data from 19 different African countries. Via the analysis, a clear link between high heat + reduced rainfall and low birth weight was found -- resulting in birth weights of under 2,500 grams (~5.5 pounds).
“In the very early stages of intra-uterine development, climate change has the potential to significantly impact birth outcomes,” stated Kathryn Grace, assistant professor of geography at the university and lead author of the study, which appeared in Global Environmental Change. “While the severity of that impact depends on where the pregnant woman lives, in this case the developing world, we can see the potential for similar outcomes everywhere."
“Women who are pregnant are more sensitive to heat stress, dehydration, etc,” though air conditioning in places like the US “would likely reduce the exposure and the stress."
Climate Progress provides more:
"In 2013, they merged health data from Demographic and Health Surveys, part of the United States Agency for International Development (USAID), with growing season data, and with temperature and rainfall data from a variety of sources. Also, they collected information on growing and livelihood from USAID’s Famine Early Warning System, and precipitation data from the climate hazards group, the first time scientists have used fine-resolution precipitation and temperature data with birth statistics to determine whether and how climate affects birth weight.
"The researchers examined nearly 70,000 births between 1986 and 2010, and coordinated them with seasonal rainfall and air temperatures, factoring in information about the mother and her household, such as education and whether the dwelling had electricity. The team then calculated the average rainfall for a given month within 10 kilometers of the infant’s birth location, gathering data for each month up to one year before the baby was born, summing the values over each trimester. They did the same with temperature records, including the number of days in each birth month when the temperature exceeded 105F and 100F as the maximum daily temperature, again summing up the values over trimesters."
What was determined was that the higher the number of days over 100° Fahrenheit (during any trimester), the lower the birth weight. The higher the temperature went over 100° and the longer such temperatures lasted, the greater the reduction in birth weight. Rainfall, on the other hand, seemed to increase birthweight.