The nearly 4.3 million births in 2006 were mostly due to a bigger population, especially a growing number of Hispanics. That group accounted for nearly one-quarter of all U.S. births. But non-Hispanic white women and other racial and ethnic groups were having more babies, too.

An Associated Press review of birth numbers dating to 1909 found the total number of U.S. births was the highest since 1961, near the end of the baby boom. An examination of global data also shows that the United States has a higher fertility rate than every country in continental Europe, as well as Australia, Canada and Japan. Fertility levels in those countries have been lower than the U.S. rate for several years, although ...