Development of personalized predictive models for non-IVF and IVF procedures in lesbian and single women sheds light on applicability of infertility biomarkers to women of unknown fertility status

Abstract

OBJECTIVE:The appearance of time lapse incubators has opened the possibility of studying dynamic embryo behaviors. Blastocyst collapse has been studied in different mammal models. Strong contractions seem to be deleterious for embryo hatching. There is a high consumption of energy in the process of contraction and re-expansion, which could affect the extrusion of the blastocyst from de Zona Pellucida (ZP) and, consequently, the possibility of implantation.DESIGN: Retrospective study to validate the results obtained from IVI Murcia and IVI Valencia (Marcos, J et al, Hum Reprod 2015) analyzing a second data set of embryos, in a different laboratory and with different culture conditions. Marcos et al. found that blastocyst collapse affects implantation, but not hatching rate. Time of collapse and duration of contraction were similar in non-implanted collapsed blastocyst (KID-CB) when compared to implanted collapsed ones (KID+ CB).MATERIALS AND METHODS: 340 cycles from the oocyte donation program of IVI Zaragoza; 499 blastocysts (both fresh and cryopreserved) were transferred, from whose 375 had known implantation data (KID).Embryos where incubated in Embryoscope TM (Vitrolife) at 37oC, 5% CO2, 5% 02 and single step media (GLOBAL, Quermed). Only strong contractions where considered for the analysis (more than 50% of Trofoectoderm (TF) detachment from ZP).Hatching rate, implantation rate, duration and time of contractions where compared between contracted (CB) and non-contracted (NCB) blastocysts.RESULTS: From the 499 blastocysts transferred, 25.1% presented at least one contraction. According with the study of Marcos et al, there were no differences in hatching rate between CB (46.8%, [CI95% 38.0-55.6]) and NCB (43.5%,), but implantation rate was statistically lower in CB (33.7%, [CI95% 24.2-43.2] compared with NCB (47%, [CI95% 41.5-53.2], P¼0.02). Taking into account only KID CB, our data agree again with Marcos respecting to duration of contraction, which is similar between ) vs 2.07 h (1.65-2.56h)), but not in the time of collapse (119.89 (116.49-123.28H) ) KID+ CB, p¼0.0002).CONCLUSIONS: Blastocyst collapse is a negative feature of embryo dynamics, as implantation is affected. Our data confirm the relevance of this parameter as it has been validated in a different setting, with different patients and culture conditions. In consecuence, this dinamic characteristic should be taken into account in the embryo selection for transfer.References:1. Collapse of blastocysts is strongly related to lower implantation succes: a time-lapse study.

The Present and Future of Embryo Cryopreservation

“…Similar results were presented from another retrospective study made by Santistevan et al [69]. It encompassed more than 16,000 IVF cases, with repeated success rates following FET versus fresh ET in women up to 35 years of age, being 50.240.3%.…”