Comparison among different Time-Lapse systems: what has changed in the laboratory?

Every year more and more couples rely on IVF to achieve pregnancy not only because of the increase of infertile couples but also because socio-economic reasons force more women to delay their pregnancy. Over 5 million children have been born in the world by IVF, fulfilling the desire of many infertile couples to have their own family. Among the risks still associated with IVF, the most important one is the risk of multiple gestation and the consequent maternal and neonatal morbidity/mortality, which has significantly increased over the past few decades. For this reason, it is necessary to improve the outcome of the IVF procedure by introducing innovative methods that not only help selecting the best embryo for transfer, but may ultimately allow to routinely perform single embryo transfers, thus eradicating the risks associated with multiple gestations. The introduction of Time-Lapse use in routine practice provides continuous, non-invasive embryo monitoring, allowing for a dynamic evaluation of the embryo development without the need to remove the embryo from optimal culturing conditions. Time-Lapse technology has also the potential to improve the process of embryo selection by implementing special algorithms. In fact the extra information on the cleavage pattern, morphologic changes and embryo development dynamics can help us to identify embryos with a higher implantation potential. In the past 5-6 years, numerous studies have been published that confirmed the safety of Time-Lapse technology, leaving the answer to improving result to a still ongoing debate. The intent of this paper is to appraise this innovative technology that on the one hand seems to be essential to make a correct selection of the embryo to be transferred, but on the other has failed until now to show its real benefits in clinical practice.