The U.S. birth rate, calculated as the annual number of births per 1,000 women between 15-44, hit an all-time low in 2011, reported Pew Research, largely attributed to the Great Recession.

While final data are not available, the rate hit 63.2 per 1,000 women last year — the lowest since 1920, before which reliable numbers are not available.

The U.S. birth rate fell by 8 percent between 2007 and 2010.