The government reported last week that U.S. births fell for the fourth year in a row in 2011, though the fall has slowed down a bit, WORLD News Service reports. Americans typically have more children in robust economic times, and "it may be that the effect of the recession is slowly coming to an end," said Carl Haub, senior demographer with the Population Reference Bureau. Falling births is a relatively new phenomenon in the U.S.; births had been on the rise since the late 1990s and hit an all-time high of more than 4.3 million in 2007. But fewer than 4 million births were counted last year -- the lowest number since 1998. Meanwhile, birth rates for teen moms have been falling since 1991 and are at historic lows. Last year the drop was 8 percent, to about 330,000 teen births -- the lowest number since 1946.