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 Even though there is little practical use for heavy horses today because their muscle power has been replaced by machinery, breeders and enthusiasts have ensured that the breed is increasing, rather diminishing in numbers.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).
Monoamniotic twins are rare, with an occurrence of 1 in 35,000 to 1 in 60,000 identical twin pregnancies. Complications[edit] The survival rate for monoamniotic twins has been shown to be as high as 81% to 95% in 2009 with aggressive fetal monitoring, although previously reported as being between 50% to 60%.