Current State of Art Embryo Selection Techniques

Assisted reproductive technologies (ARTs) have made many advancements since the birth of Louise Brown in 1978. Success rates have improved within the past four decades, but currently remain only between 40-60% successful and fertility treatments cost $12,000-$15,000 [1]. To improve pregnancy rates, two to three embryos are often transferred into the uterus of the patient or recipient in hopes of one surviving. This results in high fecundity, which is a current challenge ART is facing [2-4]. The practice of transferring multiple embryos into the uterus of non-litter bearing animals or humans is not the safest technique to the mother or fetus because it can increase likelihood of preterm labor, low birth weights, uterine growth restrictions, preeclampsia, gestational diabetes, placental abruption, fetal demise and cesarean delivery [5]. Single embryo transfer can reduce these risks but requires the ability to select the embryo with the highest chance of establishing a pregnancy which survives to term. Choosing which embryo is “best” is of much disagreement amongst embryologist, with one study demonstrating persons evaluating embryos agreed in only 68.5% of cases [6]. This indicates that even the most expert, professional embryologist cannot always determine which embryo has the greatest likelihood of establishing a pregnancy, surviving to term and creating a healthy baby. The objective of the present review is to provide an overview of methods currently employed in ART which will help predict high quality embryos.