A multiple birth occurs when more than one fetus is carried to term in a single pregnancy. Different names for multiple birth are utilized, depending on the number of offspring. Common multiples are two and three, known as twins and triplets respectively. Twins, triplets and other multiple births occur to varying degrees in most animal species, although the term is most applicable to placental species. There are two common types of multiple births, fraternal (dizygotic) and identical (monozygot… (More on Sextuplet)