(AP Photo)

(CNSNews.com) - The fertility rate of women in the United States fell to a record low for the second year in a row in 2012, according to data released last week by the federal Centers for Disease Control and Prevention.

Also for the second year in a row, 40.7 percent of the babies born in the United States were born to unmarried mothers.

The fertility rate is the number of births per 1,000 women aged 15-44. In 2012--according to the Dec. 30, 2013 CDC report “Births: Final Data for 2012"--the U.S. fertility rate was 63.0. That was down from 63.2 in 2011, the previous all-time low.

“The 2012 general fertility rate (GFR) for the U.S. was 63.0 births per 1,000 women aged 15–44, down slightly (less than 1%) from the record low rate reported for the nation in 2011 (63.2),” said the CDC report.

The U.S. fertility rate has dropped from year-to-year for each of the last five years. In 2007, it was 69.3. In 2008, it was 68.1. In 2009, it was 66.2. In 2010, it was 64.1. In 2011, it was 63.2. And, in 2012, it was 63.0.

Since 1960, the fertility rate in the United States has declined 46.6 percent. In that year, 118 babies were born per 1,000 women aged 15 to 44.

Of the 3,952,841 babies who were born in the United States in 2012, said the CDC report, 1,609,619—or 40.7 percent--were born to unmarried mothers.

2012 thus marked the fifth straight year that 40 percent or more of the babies born in the United States were born to unmarried women.

In 2008, the first year when 40 percent or more of the babies born in the United States were illegitimate, 40.6 percent of babies were born to unmarried women.

In 2009, 41.0 percent of American babies were born to unmarried women. In 2010, it was 40.8 percent. In 2011, it was 40.7 percent. And, in 2012, it was 40.7 percent.

The percentage of American babies born to unmarried mothers has more than doubled since 1980. That year, only 18.4 percent of the babies born in the United States were born to unmarried mothers.