Number of embryos to transfer: Better safe than sorry?

摘要

Guidelines on the number of embryos to be transferred in couples attempting assisted conception is widely debated owing to adverse perinatal risks and costs associated with multiple pregnancies. In published work on perinatal outcomes after assisted conception, it is generally agreed that the high prevalence of twins explains most of the increased risk in pregnancies after assisted conception.1 Opinion has, therefore, shifted towards the view that transfer of only one embryo at a time is optimum.