Performance
24sure is a novel technique with the potential to transform the way in which IVF is used to treat infertility, recurrent miscarriage and inherited genetic disorders. At this stage in its development it is therefore reasonable to ask for objective measures of 24sure’s impact on live birth rate.
This simple question is difficult to answer because the technical performance of 24sure, measured by its ability to reliably screen aneuploidy in single cells, is only one part of a complex biological process that results in a live birth.
BlueGnome has performed a number of studies in conjunction with researchers to validate accurate technical performance in detecting aneuploidy from single cells, including a cell line study, and various concordance studies which are to be published.
In June 2010 the European Society of Human Reproduction and Embryology (ESHRE) presented the results of a two centre pilot study which confirmed that 24sure is able to predict aneuploidy in 89% of cases. A number of peer reviewed papers are anticipated following the trial, as soon as they are available we will report them here.
BlueGnome has also established the percentage of single cells which should be expected to generate a result via 24sure through assessment of 310 IVF cycles performed in Sure Laboratories in Cambridge.
The more important question of whether 24 chromosome aneuploidy screening translates into improved live birth rates and reduced miscarriage rates will ultimately be answered through a combination of clinical studies and other research published in the scientific literature. Recent papers that came out towards the end of 2010 show initial validation and evaluation of 24sure.
The study by Gutierrez et al. (2010) analysed 634 day 3 embryos with SurePlex and 24sure, 97.5% gave clear well-defined results, of those 35.4% were euploid and the rest were aneuploid. 54 abnormal embryos were reanalysed using FISH to establish an error rate for the 24sure. Of the 54 embryos, only one disagreed with the FISH result and was thought to be mosaic, but did not result from a technical failure. Normal embryos were identified for transfer in 76 individuals, which resulted in 44 pregnancies, 40 ongoing or going to term, resulting in a 10% miscarriage rate.
Fragouli et al. (2010) carried out a smaller study to investigate mosaicism and aneuploidy in blastocysts and to evaluate the effectiveness of metaphase CGH and 24sure analysis compared with FISH. Twenty blastocysts were tested with 24sure and metaphase CGH, all samples gave results, indicating a 100% diagnosis rate. Of all the embryos analysed with all methods (52) chromosome anomalies were identified in 21 cases, 13 uniformly anueploid, plus 8 mosaic anueploid with normal cells.
A number of publications are anticipated through 2011 and will be referenced by this site as they are published.