Positive outcome after preimplantation diagnosis of aneuploidy in human embryos

Chromosomal abnormalities are responsible for a great deal of embryo wastag e, which is reflected, at least partially, in decreased implantation and in creased miscarriage in older women, To address this problem the transfer of only chromosomally normal embryos previously selected by preimplantation g enetic diagnosis (PGD) has been proposed. We designed a multi-centre in-vit ro fertilization (IVF) study to compare controls and a test group that unde rwent embryo biopsy and PGD for aneuploidy, Patients were matched retrospec tively, but blindly, for average maternal age, number of previous IVF cycle s, duration of stimulation, oestradiol concentrations on day +1, and averag e mature follicles. All these parameters were similar in test and control g roups, Only embryos classified as normal for those chromosomes were transfe rred after PGD, The results showed that the rates of fetal heart beat (FHB) /embryo transferred between the control and test groups were similar. Howev er, spontaneous abortions, measured as FHB aborted/FHB detected, decreased after PGD (P < 0.05), and ongoing pregnancies and delivered babies increase d (P < 0.05) in the PGD group of patients, Two conclusions were obtained: ( i) PGD of aneuploidy reduced embryo loss after implantation; (ii) implantat ion rates were not significantly improved, but the proportion of ongoing an d delivered babies was increased.