P40 Short-CGH in a PGD for a reciprocal translocation: first clinical application

Abstract

Introduction: An increase of embryonic chromosome abnormalities with maternal age contributes to low implantation rates and high miscarriage rates. PGS may reduce this trend by selecting chromosomally normal embryos for replacement, provided that the biopsy is done with minimal damage to the embryo and the analysis is accurate. Unfortunately, different studies using day-3 biopsy and FISH have used diverse methodologies yielding conflicting results. Although day 5 biopsy, CGH and vitrification combined seem to produce outstanding results, patients and doctors still prefer fresh over frozen cycles. An improvement over CGH is array CGH (aCGH), which provides complete chromosome analysis in one day. The Here we present our preliminary clinical data on the use of aCGH. Methods: aCGH was performed on 87 cycles from 19 fertility centers. Average maternal age was 37.6. The indications were advanced maternal age ( 38, n = 46), recurrent pregnancy loss (RPL, n = 28) or other (n = 13). A single cell was biopsied per embryo on day 3 of development. Normal embryos were replaced on day 5. Some abnormal embryos were fully fixed and reanalyzed by FISH to determine the error rate of the technique. Pregnancy rates and miscarriage rates from each center were compared to SART data from the same center controlling for age. Results: A total of 747 embryos were analyzed. 2.4% of cells did not show DNA amplification. Of the rest 38% were euploid and the rest abnormal. Euploidy decreased with maternal age from 45.7% in Conclusions: aCGH provides results in one day with very low no result frequency (2%) and error rate (5%). Pregnancy and miscarriage rates seem to indicate an improvement over historic controls. While comparing pregnancy rates in this manner may be subject to confounding factors, miscarriage rates are probably even higher in an ideal control that should include >25% RPL patients.