The first stage is genetic counseling by a geneticist, who, working closely with a clinician, will inform the couple whether the PGD/PGS techniques are recommended in their case.

The procedure followed in the embryology lab  is the same procedure as a routine IVF until the day of embryo biopsy. Recent studies show that the ideal day to perform embryo biopsy is the 5th day after oocyte retrieval, when the embryos are at the blastocyst stage.

The cells retrieved from each embryo are submitted to the genetics lab for analysis. If the results can be analysed within 24 hours, embryo transfer can take place the following day (on the 6th day after oocyte retrieval). If more time is needed, the embryos can be frozen after the biopsy until their screening is completed and the healthy embryos are thawed and transferred to the next cycle.

In certain cases, the biopsy can be performed on the 3rd day of embryo culture, when the embryo is at the 8-cell stage. Despite the fact that this will allow more time for genetic analysis, it engenders a greater possibility of failure to obtain a result from this analysis.