Current practices and regulations for embryo transfer worldwide: Implications on IVF outcome

Abstract

The practice of transferring multiple embryos in an in vitro fertilization (IVF) cycle has led to an iatrogenic epidemic of multiple pregnancies. IVF multiple pregnancies cause significant morbidity and mortality for both mothers and infants, and place a substantial financial burden on the couple and the society. While increasing awareness of these problems has led to a decrease in the average number of embryos transferred, multiple embryo transfer remains the norm in most countries and results in multiple pregnancy rates of 20-30 % worldwide. Recently, several countries have placed legal restrictions on the number of embryos transferred in return of government reimbursement for IVF. Such policy seems to dramatically decrease multiple pregnancies while maintaining pregnancy rates and increasing access to treatment. Better selection of gametes and implantation competent embryos will undoubtedly increase the adoption of elective single embryo transfers and further contribute to a decrease in IVF multiple pregnancies.