When it’s very hot, or it’s very cold, this is not trivial for pregnant women. And researchers point to the fact that extreme temperatures could slow down the development of fetuses, especially at the lung level and in girls in particular, as revealed by a study published in the journal JAMA Network Open.
“The thermoregulation put in place by the body in response to temperature variations requires an adaptation of blood flow and maternal cardiac function which, when it occurs during pregnancy, can be detrimental to the fetus“, note the Inserm researchers. To better understand the effects on the respiratory system of unborn babies, they studied this issue of ambient temperature as part of a cohort, called SEPAGES: Monitoring of Exposure to Atmospheric Pollution during Pregnancy and Effect on Health.
Lower breathing performance
343 women were followed during their pregnancy and at the beginning of the infant’s life. Tests were carried out on their ability to breathe : the volume of inspired and expired air, the respiratory rate, their functional residual capacity (what remains in the lungs after expiration) were observed. Then girls and boys were compared.
They came to the conclusion that only the girls had seen their respiratory function altered by this exposure in utero at extreme temperatures. They had a lower residual functional capacity and a higher respiratory rate than little girls who had not been exposed to these extreme temperatures.
“The variations observed are not of a pathological nature and do not make it possible to predict a respiratory disorder subsequently.. But the various measurements of lung function carried out all converge towards an association in the little girl between exposure in utero to high or low temperatures and poorer lung performance in the newborn., says an Inserm researcher. Several years will be needed before testing these children again to find out if these effects persist in the long term.
Source: Extreme Temperatures in Pregnancy: A Possible Impact on the Lung Development of Infant Girls, Inserm, March 17, 2023.
