Live-Birth Rate Associated With Repeat In Vitro Fertilization Treatment Cycles

Abstract

In vitro fertilization (IVF) is commonly stopped after 3 or 4 unsuccessful embryo transfers,^1,2 with 3 unsuccessful transfers labeled “repeat implantation failure.”³ This practice has been influenced by a study of 1328 embryo transfers undertaken 20 years ago, without use of intracytoplasmic sperm injection (ICSI), which reported a decline in live-birth rates after the fourth cycle.⁴ With 1 exception,⁵ previous studies of cumulative pregnancy or live-birth rates have been relatively small, with limited ability to precisely estimate cumulative success beyond 4 transfers.^4,6-9 Previous studies have defined a cycle of IVF as an embryo transfer.^5-9 Thus, each initiation of IVF with ovarian stimulation has been treated as several separate cycles whenever there has been a series of repeated embryo transfers. Because both the promotion of single embryo transfer and the effectiveness of freezing embryos have increased markedly over the last 10 to 15 years,^10-15 it has been suggested that IVF success should be calculated as the live-birth rate per initiated ovarian stimulation, including all subsequent separate fresh and frozen embryo transfers.^5,10-13