Personalized medicine or 'one size fits all'?

摘要

It is not too much of a stretch to assert that the "holy grail" of assisted reproductive technology (ART) has been the selection and transfer of a single embryo that will result in a successful and healthy pregnancy. Due in large measure to improvements both in stimulation strategies and laboratory technique, the efficiency of implantation following in vitro fertilization (IVF}/embryo transfer has improved dramatically over the last few decades. As pregnancy rates have improved, multi-fetal pregnancies have risen to the fore as the dominant risk of ART. The worldwide promulgation of national, legislative and voluntary professional guidelines limiting the number of embryos transferred has resulted in a marked reduction in the rates of higher-order multiple gestations, but thus far has had a minimal impact on the incidence of twin gestations (1).