There can be different types of quadruplets just as there are different types of triplets. There can be any combination of fraternals and identicals within the four. According to data from the Triplet Connection and Mothers of Supertwins (MOST), close to 60 percent of the families registered with these organizations have a combination of identical and fraternal children. Many of the other higher order multiples result from multiple ovulations and thus are fraternal. Identical quads, where all four are genetically identical, is extremely rare.