Sweltering heat or icy temps — equally unpleasant; now add pregnancy to such less than favourable climes and the discomfort is exponential.
But beyond Sweat City, or the struggle to get on (or fit into) your winter garb, there’s another effect that extreme hot or cold weather can have – on your unborn baby, specifically.
According to a recent study, unusually high or low temperatures during the second or third trimesters may play a part in babies being born with low birth weight.
Analysing 220,000 babies delivered across 19 U.S. hospitals, researchers at the National Institutes of Health compared the newborns’ birth weight patterns to the prevailing weather conditions at the time of gestation.
“Low birth weight babies” were defined as those babies born after 37 weeks and weighing less than 5.5 lbs at the time of birth.
The researchers discovered a surprising connection between ambient temperatures and birth weight: mums-to-be who were exposed to severely cold weather during their second or third trimesters had an 18 to 21 percent greater chance of giving birth to babies in the low weight percentile, while those who were exposed to a similar degree of cold throughout pregnancy had a 257 percent greater chance of having low birth weight babies.
When the mercury skyrocketed, the researchers also noted a correlative climb in low birth weight risk; 31 percent increase in those mothers suffering through abnormally hot temperatures during the final trimester, and a whopping 249 percent increased risk for those exposed to the heat for the duration of pregnancy.
If you suddenly experience an unseasonable spike or drop in weather temp, protect your bump by staying indoors as much as possible, and don’t panic. The study’s observed relationship between low birth weight and weather has not yet been determined as causal; still, it’s a good reminder of the delicate balance inside your womb that could be disturbed by external factors.