What is the risk of multiple pregnancies with in vitro fertilization?
New in vitro techniques have resulted in fewer high order multiple births (triplets or more), because fewer embryos are transferred. Ten years ago, 3 or 4 embryos needed to be transferred to achieve a pregnancy rate of 25-30%, even when the woman was under age 35. This resulted in an unacceptably high number of triplets and quadruplets.
Today, we achieve approximately twice the success rate in women under 35 despite transferring only two embryos. This high success rate with transferring fewer embryos has decreased the incident of high order multiple pregnancies in our in vitro fertilization program.