ATLANTA — Remember the baby boom? No, not the one after World War II. More babies were born in the United States in 2007 than any other year in the nation's history — and a wedding band made increasingly little difference in the matter.
The 4,317,119 births, reported by federal researchers Wednesday, topped a record first set in 1957 at the height of the baby boom.
Behind the number is both good and bad news. While it shows the U.S. population is more than replacing itself, a healthy trend, the teen birthrate was up for a second year in a row.
The birthrate rose slightly for women of all ages, and births to unwed mothers reached an all-time high of about 40 percent, continuing a trend that started years ago. More than three-quarters of these women were 20 or older.
For a variety of reasons, it has become more acceptable for women to have babies without a husband, said Duke University's S. Philip Morgan, a leading fertility researcher.
Even happy couples may be living together without getting married, experts say. And more women — especially those in their 30s and 40s — are choosing to have children despite being single.
The new numbers suggest the second year of a baby boomlet, with U.S. fertility rates higher in every racial group, the highest among Latinas. On average, a U.S. woman has 2.1 babies in her lifetime. That is the "magic number" required for a population to replace itself.
"I expect they'll go back down. The lowest birth rates recorded in the United States occurred during the Great Depression — and that was before modern contraception," said Dr. Carol Hogue, an Emory University professor of maternal and child health.