Time to live birth: towards a common agreement.

The major purpose of a couple at the first infertility appointment is to get a healthy baby as soon as possible. From diagnosis and decision on which assisted reproduction technique (ART) and controlled ovarian stimulation, to the selection of which embryo to transfer, the dedicated team of physicians and embryologists puts all efforts to shorten the time to pregnancy and live birth. Time seems thus central in assisted reproduction, and we can conveniently use it as a measure of treatment efficiency. How can we measure time to live birth? What timelines do we need to consider to evaluate efficiency? In this paper, we will discuss the importance of "Time" as a fundamental parameter for measuring ART success.