Time-lapse imaging of preimplantation embryos.

Time-lapse imaging of preimplantation embryos is a relatively new and developing technology that may allow embryologists to be more objective in scoring embryos, and allow better selection of embryos for transfer and cryopreservation. The technology is easily assimilated into the in vitro fertilization (IVF) laboratory and is used with any preferred culture medium and culture environment. Embryos are loaded into dedicated culture dishes or trays which allow for individual embryo tracking and in some devices, group culture and individual embryo scoring at the same time. The embryos are imaged at regular intervals without removal from the culture environment, and the images can be viewed individually or stitched together to form a video showing complete development from oocyte to blastocyst. Automated or manual review of time-lapse videos can assist in identifying embryos with normal developmental profiles, and in deselecting embryos for consideration for transfer based on abnormal phenotypes. Time-lapse data are used in conjunction with traditional embryo scoring based on morphology to make embryo selection decisions. Improved embryo selection for transfer could allow for more widespread use of elective single embryo transfer without compromising pregnancy rates after IVF. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.