(CNN) - Fewer babies were born in the United States last year than at any time in the past 32 years.
Preliminary numbers from the Centers for Disease Control show the birth rate dropped 2 percent from 2017.
The biggest decrease was in teen mothers. The birth rate dropped 7 percent among women 15 to 19 years old. It also dropped 4 percent among women 20 to 24, 3 percent among women 25 to 29 and 1 percent among women 30 to 34.
The rate actually rose among women 35 to 44 and stayed the same for mothers 45 and older. In all, about 3.8 million babies were born in the U.S. last year.
The U.S. population is not producing enough babies to replace itself, but that's not new. The fertility rate has generally been below its replacement value since 1971.