The perils of climate change: In utero exposure to temperature variability and birth outcomes in the Andean region.

•We explore the effect of in utero exposure to temperature variability on birth outcomes.•We focus on three developing countries in the Andean region.•Increasing temperature variability during pregnancy reduces birth weight by 20g.•Temperature variability increases the incidence of low birth weight.•Evidence suggests that food insecurity and reduced health care explain the results.