Meet the Clydesdale. The Clydesdale breed once almost faced extinction. Even though there is little practical use for heavy horses today because their muscle power has been replaced by machinery, breeders and enthusiasts have ensured that the breed is increasing, rather diminishing in numbers.
1 Over the three decades, the twin birth rate rose by 76 percent, from 18.9 to 33.2 per 1,000 births (or from 1.9 percent to 3.3 percent of all births) (Figure 1). 2  Increases in the twin birth rate averaged more than 2 percent a year from 1980 through 2004 (peaking at more than 4 percent from 1995 to 1998).
Twin Births in the U.S., Like Never Before. More twins are being born in the United States than ever before. From 1980 to 2009, according to a recent report by the National Center for Health Statistics, the rate of twin births rose 76 percent. Now about one in 30 babies born in the United States is a twin.