Ever since several highly publicized and probably ill-advised multiple births became fodder for the media, the question of how many embryos should be implanted has been discussed openly. The American Society for Reproductive Medicine (ASRM) published a 2013 guideline addressing the number of embryos to transfer. Its guideline relied on empiric data to individualize patient care while minimizing the risk of high-order multiple (HOM; 3 or more offspring) births. The guideline considers patient age and prognosis also. One gap in the guideline is recommendations for women older than age 42; its authors noted that more study is needed before evidence-based recommendations can be made.
Embryo Transfers and Multiple Births: Doing the Math in Reproductive Endocrinology
