In cases of IVF and ICSI, it is possible to test the chromosomes of one or two cells of the embryo at an early stage of development, before the embryo is transferred back into the uterus. Removal of one or two cells of the embryo does not in any way harm the future development of the embryo. Testing is limited to looking at few specific chromosomes (using FISH) that are suspected to give trouble for the couple rather than the entire Karyotype. The technique is rapid and the report can be given in 12 – 24 hours before the embryo is put back into the uterus.