5. EUPLOID BLASTOCYSTS HAVE SIMILAR CLINICAL OUTCOME REGARDLESS OF THEIR D5 KIDSCORE™

Abstract

Introduction Time-lapse monitoring (TLM) uses morphokinetics assessment and annotation models such as KIDScore™ to help predict the implantation potential of a blastocyst. Meanwhile, preimplantation Genetic Testing for Aneuploidy (PGT-A) determines the chromosomal status of an embryo, allowing the identification of embryos with the correct number of chromosomes. Theoretically, combining both of these advanced technologies in IVF may enable the selection of a competent blastocyst for transfer, thus maximising the chance of a successful pregnancy. To the best of our knowledge, the significance of KIDScore™ annotation model in euploid blastocysts has not been studied. This is a retrospective study to assess the clinical outcomes of elective frozen embryo transfer (eFET) of euploid blastocysts in various D5 KIDScore™ groups in Alpha Fertility Centre, Malaysia, between January to November 2018. Material and Methods Two hundred and twenty-one (221) patients aged 18 – 45 years (mean age 30.8 years) had their embryos cultured to blastocyst stage in the Embryoscope™ incubator (Vitrolife, Sweden) and screened using Next Generation Sequencing (Ion Torrent, USA). In order to accurately determine the D5 KIDScore™ of the euploid blastocysts transferred, only blastocysts intended for single frozen embryo transfer were included in this study. All the 221 blastocysts transferred were categorised according to D5 KIDScore™ ranged between 1.0 – 4.0 (Group A, n = 4), 4.1 – 5.0 (Group B, n = 4), 5.1 – 6.0 (Group C, n = 15), 6.1 – 7.0 (Group D, n = 49), 7.1 – 8.0 (Group E, n = 83), 8.1 – 9.0 (Group F, n = 53), and 9.1 – 9.9 (Group G, n = 13) respectively. Clinical pregnancy and number of gestational sacs were determined by ultrasound. Results The clinical pregnancy rates and implantation rates for Group A, B, C, D, E, F and G were 25.0%, 75.0%, 66.7%, 46.9%, 60.2%, 60.4% and 53.8% respectively. The miscarriage rates for Group A, B, C, D, E, F and G were 0.0%, 33.3%, 20.0%, 4.3%, 6.0%, 12.5% and 14.3% respectively. There was no significant difference in clinical pregnancy rate, implantation rate and miscarriage rate between all groups (p>0.05). Conclusions Our study shows no significant difference in clinical pregnancy rate, implantation rate and miscarriage rate across all D5 KIDScore™ groups for euploid blastocysts. Euploid blastocysts with lower D5 KIDScore™ gives comparable clinical outcomes of that to blastocyst with higher D5 KIDScore™ and should be considered in the selection for transfer. D5 KIDScore™ may serve as a guide for selection of blastocyst with high implantation potential. However, PGT-A still remains the more reliable method compared to solely relying on D5 KIDScore™ in TLM for blastocyst selection. Nevertheless, further studies with a larger sample size should be carried out to ascertain the significance of D5 KIDScore™ in blastocyst that was screened euploid using PGT-A.