Doctors routinely transfer multiple embryos to increase the likelihood that at least one will result in a pregnancy . 80 % of twins , 77 % of triplets , other twins came from fertility treatments in 2011 . More twins are the result of the mother taking fertility drugs rather than having IVF . The IVF - triplet trend peaked in 2012 due in part to new medical guidelines .
80 % of twins , 77 % of triplets , other twins came from fertility treatments in 2011 . More twins are the result of the mother taking fertility drugs rather than having IVF . The IVF - triplet trend peaked in 2012 due in part to new medical guidelines .