Elective single embryo transfer- the power of one

Abstract

Despite the highest historical live birth success rates for couples undergoing in vitro fertilization (IVF), there has been an epidemic of iatrogenic twin and higher order gestation conceived from this treatment. Continued improvement in cryopreservation techniques have allowed preservation of supernumerary embryos for use in future cycles, and refinements in culture systems and embryo selection have resulted in the transfer of fewer embryos while maintaining favorable pregnancy rates. The voluntary transfer of a single high quality embryo, elective single embryo transfer (eSET), has significantly reduced multiple gestation rates and maximized the rate of singleton pregnancy without compromising overall success rates. Although eSET is the standard of care in several developed countries, utilization in the United States has been slow. States with mandated IVF insurance have seen decreases in preterm birth rates yielding down stream health care savings. Herein, the evolution and future applications of this practice to reduce the risk of iatrogenic twins is reviewed.

Keywords: Elective single embryo transfer; In-vitro fertilization; Infertility; Twin gestation assisted reproductive technology.

Fig. 1

Desired treatment outcome a before education and b after education. Reprinted from Fertil Steril, 88/2, Ryan et al. A mandatory single blastocyst transfer policy with educational campaign in a United States IVF program reduces multiple gestation rates without sacrificing pregnancy rates, 354–60, Copyright (2007), with permission from Elsevier [39]

Fig. 2

Cycles with single embryo transfer. Trends in the percentage of cycles using elective single embryo transfer, United States from 2005 to 2013. The data source for this figure was the Society for Assisted Reproductive Technology (SART) Clinic Outcomes Reporting System (CORS) database (http://www.sart.org)