Pregnancy achieved by transfer of a single blastocyst selected by time-lapse monitoring

Appropriate selection of a single blastocyst for transfer decreases the risk of multiple gestations. By using a compact time-lapse microscope system placed inside a regular incubator, combined with a microwell embryo culture dish, the development of all the embryos from a patient was continuously monitored by obtaining images at 10 min intervals. The embryos were not moved during the time-lapse observation. The system was switched off completely between image acquisitions in order to avoid exposure to electromagnetic radiation. The analysis of time-lapse records was used to choose a single blastocyst for transfer, which resulted in a singleton pregnancy and birth of a healthy boy on term

Prediction of in-vitro developmental competence of early cleavage-stage mouse embryos with compact time-lapse equipment

Single blastocyst transfer is regarded as an efficient way to achieve high pregnancy rates and to avoid multiple pregnancies. Risk of cancellation of transfer due to a lack of available embryos may be reduced by early prediction of blastocyst development. Time-lapse investigation of mouse embryos shows that the time of the first and second cleavage (to the 2- and 3-cell stages, respectively) has a strong predictive value for further development in vitro, while cleavage from the 3-cell to the 4-cell stage has no predictive value. In humans, embryo fragmentation during preimplantation development has been associated with lower pregnancyrates and a higher incidence of developmental abnormalities. Analysis of time-lapse records shows that most fragmentation is reversible in the mouse and is resorbed in an average of 9 h. Daily or bi-daily microscopic checks of embryo development, applied routinely in human IVF laboratories, would fail to detect 36 or 72% of these fragmentations, respectively. Fragmentation occurring in a defined time frame has a strong predictive value for in-vitro embryo development. The practical compact system used in the present trial, based on the ‘one camera per patient’ principle, has eliminated the usual disadvantages of time-lapse investigations and is applicable for the routine follow-up of in-vitro embryo development