Time-lapse monitoring has the potential to increase the success rate of IVF treatments. The aim of the 'SelecTIMO study' is to evaluate if the application of time-lapse monitoring can indeed increase the pregnancy rate through more stable culture conditions and / or optimized embryo selection procedures. The Geri+ time-lapse incubator records the development of embryos every 5 minutes and provides images that can be used by embryologists and IVF technicians for the selection of human embryos for transfer.