Preimplantation genetic diagnosis for chromosome rearrangements - one blastomere biopsy versus two blastomere biopsy.

PURPOSE: Preimplantation Genetic Diagnosis (PGD) has proven to be a useful reproductive option for carriers of some chromosome rearrangements. The data presented in this study compares the impact of one versus two blastomere biopsy on the likelihood of achieving a PGD result, as well as the effect on subsequent embryo development and clinical outcomes. METHODS: IVF-PGD couples had either one or two blastomeres biopsied from all embryos with ≥7 blastomeres on day 3 post oocyte collection. These blastomeres were assessed for the specific chromosome rearrangement using Fluorescent In-situ Hybridisation (FISH). Further embryo development was monitored on days 4 and 5. Clinical outcomes were assessed retrospectively. RESULTS: The data shows that statistically more embryos achieved a PGD result following two blastomere biopsy, compared with one blastomere biopsy (92 % versus 88 %, respectively). Furthermore it was found that embryo development and clinical outcomes were similar between the two biopsy groups. CONCLUSIONS: Based on this analysis it appears that the biopsy of two blastomeres from embryos with ≥7 blastomeres on day 3 is a valid and successful approach for couples presenting for IVF-PGD for a chromosome rearrangement.

Preimplantation genetic screening outcomes are associated with culture conditions.

BACKGROUND: Although preimplantation genetic screening (PGS) is widely offered, there are contradictory reports on the clinical merit of this procedure. Any gain from embryo selection following aneuploidy screening must significantly outweigh the impact of the procedure. Variability of technical expertise in embryo biopsy, blastomere fixation, fluorescence in situ hybridization analysis, along with suboptimal laboratory quality control and inappropriate patient selection may impact PGS outcomes. METHODS: To investigate such effects, a total of 1508 stimulated in vitro fertilization (IVF) cycles were retrospectively analysed. During 2004, a significant change was made to the embryo culture media used. Clinical outcomes from cycles with PGS were compared prior to and after the change in media and compared with matched controls not utilizing PGS during the same period. RESULTS: Clinical PGS success rates were found to improve following the media change. For patients aged less than 40, clinical outcomes following PGS were significantly lower than those without PGS prior to the change, but became equivalent after the change. For patients >or=40 years and