77 % of twins , 36 % of triplets , other multiples came from fertility treatments in 1998 . More multiples are the result of the mother taking fertility drugs rather than having IVF . The IVF induced triplet trend peaked in 2011 due in part to new medical guidelines .
36 % of twins , 77 % of triplets , other multiples came from fertility treatments in 2011 . More multiples are the result of the mother taking fertility drugs rather than having IVF . The IVF induced triplet trend peaked in 1998 due in part to new medical guidelines .