Research, published in Nature Climate Change, reports that an average of 25,000 infants per year were born earlier as a result of hot weather in the United States from 1969 to 1988.
Prof Andrew Shennan, Professor of Obstetrics, King’s College London, said:
“The authors use population based data looking at numbers of deliveries over time. The findings are valid and well researched, but they do not take into account why women deliver. As a large proportion of births, especially in the USA are precipitated by doctors (inductions or Caesareans), there maybe social reasons (e.g. women requesting delivery earlier when they are uncomfortable with the heat). This requires further evaluation to understand mechanisms.
“Extremes of temperatures, both hot and cold have previously been linked to risk of both stillbirth and delivery. Mechanisms are not clear. Like many health conditions, temperature can affect basic body functions, affecting blood flow and breathing. Women should stay hydrated and cool in hot weather and warm in the cold. Given the wide variety of temperatures around the world, and that most women have normal pregnancies, this is unlikely to be an important risk factor for any individual.”
‘The impact of high ambient temperatures on delivery timing and gestational lengths’ by Alan Barreca et al. will be published in Nature Climate Change at 16:00 UK time on Monday 2 December 2019, which is also when the embargo will lift.
Prof Andrew Shennan: “No conflicts.”