Last year, the number of US-born babies surprisingly declined to 3,977,775 from 3,988,076 in 2014. Births peaked in 2007 at 4,316,233, slightly ahead of 1957 with 4,300,000 births! In 2015, the number of live births per 1,000 women ages 15-44 tied the all-time low of 62.5; in 1957 it was 122.9; hello Boomers! In 2015, 2,500 children were born to women younger than 15; 8,900 to women over 44.