In order to improve success rate by assisted reproductive techniques new techniques are being developed for selection of the embryo with best chance of implantation, establishement of pregnancy and subsequent delivery.The present study is based upon the hypothesis that time-lapse (frequent imaging) may give information about important steps in embryonic development, which could help to optimize selection of embryo(s) for treatment in IVF. The present study evaluates the outcome of conventional embryo culture with culture in a specially developed incubator equipped with a time-lapse system (Embryoscope).

Embryos from 50 IVF cycles (400 embryos) will be randomised to either conventional incubation or to culture in the Embryoscope. Embryos will be cultured for five days to the blastocyst stage. The primary endpoint is fraction of embryos developed to the four cell stage.

In vitro fertilization for infertility has a success rate on average in Europe of 25% in terms of baby take-home rate per cycle. One way to improve this rather low succes rate is to develop new measures for selection of the best embryo among peers as presently evaluated by embryo morphology. One of these promising methods is contineous imaging of embryo development by time-lapse. A new and unique equipment for this purpose - an Embryoscope - har been developed by Unisense Fertilitech. The present study evaluates embryo 4-cell rate during cultivation to blastocyst stage in a conventional incubator with 4-cell rate in the Embryoscope to ensure non-inferiority of the latter.

Inclusion Criteria:

• Patients undergoing 2.nd or 3.rd IVF cycle with expected retrieval of 8 oocytes or more. Age < 38 years

Exclusion Criteria:

• Endometriosis