More fascinating new research on how our environment affects babies –

Extremely hot weather appears to prompt early labor, leading to as many as 25,000 early births every year in the U.S., according to a study published Monday.

The research, published in the journal Nature Climate Change, analyzed data on 56 million births from 1969 to 1988, matching the birth dates to weather events in the counties where babies were born.

“We saw a spike in births on hot days,” said study author Alan Barreca, an associate professor in environmental economics at the University of California, Los Angeles. For example, Barreca noticed a 5 percent increase in birth rates on days that were over 90 degrees Fahrenheit.

But when researchers looked at birth rates over the days and weeks that followed extreme heat events, they found a decline in births. That decline, the study suggests, is the result of births taking place earlier than expected.

Source: Very hot weather prompts early births, study says