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3 results

  • Prolonged interval time between blastocyst biopsy and vitrification compromised the outcomes in preimplantation genetic testing

  • Shun Xiong, Jun Xia Liu, Dong Yun Liu, Jia Hong Zhu, Xiang Wei Hao, Li Hong Wu, Yang Gao, Jing Yu Li, Guo Ning Huang
  • Journal:
    Zygote / Volume 29 / Issue 4 / August 2021
    Published online by Cambridge University Press:
    18 February 2021, pp. 276-281

  • This study aimed to evaluate to what extent the different interval times between trophectoderm (TE) biopsy and vitrification influence the clinical outcomes in preimplantation genetic testing (PGT) cycles. Patients who underwent frozen embryo transfer (FET) after PGT between 2015 and 2019 were recruited. In total, 297 cycles with single day 5 euploid blastocyst transfer were included. These cycles were divided into three groups according to the interval times: <1 h group, 1–2 h group, and ≥2 h group. Blastocyst survival, clinical pregnancy, miscarriage, and ongoing pregnancy rates were compared. The results showed that, in PGT-SR cycles, survival rate in the ≥2 h group (96.72%) was significantly lower than in the <1 h group (100%, P = 0.047). The clinical pregnancy rate in the ≥2 h group was 55.93%, significantly lower than in the <1 h group (74.26%, P = 0.017). The ongoing pregnancy rates in the 1–2 h group and the ≥2 h group were 48.28% and 47.46%, respectively, significantly lower than that in the <1 h group (67.33%, P < 0.05). The miscarriage rate in the 1–2 h group was 18.42%, significantly higher than that in the <1 h group (5.33%, P = 0.027). In PGT-A cycles, the clinical pregnancy and ongoing pregnancy rates in the <1 h group were 67.44% and 53.49%, respectively, higher than that in the 1–2 h group (52.94%, 47.06%, P > 0.05) and the ≥2 h group (52.63%, 36.84%, P > 0.05). In conclusion, vitrification of blastocysts beyond 1 h after biopsy significantly influences embryo survival and clinical outcomes and is therefore not recommended.

  • Chapter 16 - Quality control and quality assurance in preimplantation genetic diagnosis

  • from Section 2 - Procedures used in preimplantation genetic diagnosis
  • Edited by Joyce Harper, University College London
  • Book:
    Preimplantation Genetic Diagnosis
    Published online:
    09 November 2009
    Print publication:
    28 May 2009, pp 247-258

  • Summary

    This chapter discusses current methodology and the advantages and limitations of blastocyst biopsy. The first phase of blastocyst biopsy involves making a hole in the zona pellucida (ZP). The dissection of the ZP may be performed mechanically, by the application of acid Tyrodes solution, or through the use of laser technology. The cryopreservation of biopsied embryos continues to be one of the weak points of preimplantation genetic diagnosis (PGD). The results published by most groups show that embryos with an opening in the ZP are more sensitive to the freezing process, which is reflected in reduced survival and developmental rates among frozen-thawed biopsied embryos. Vitrification as an alternative to classical freezing techniques is adopted as part of numerous in-vitro fertilization (IVF) programs due to its simplicity and, above all, the excellent results obtained not only in oocytes but also in early embryos and blastocysts.

  • 12 - Clinical aspects of preimplantation genetic diagnosis

  • Edited by Paul Serhal, Caroline Overton
  • Book:
    Good Clinical Practice in Assisted Reproduction
    Published online:
    22 October 2009
    Print publication:
    01 July 2004, pp 209-225

  • Summary

    Couples referred for preimplantation genetic diagnosis (PGD) are known to be at genetic risk due to an affected family member or the birth of an affected child. PGD involves three stages: IVF, embryo biopsy and single cell diagnosis. Polymerase chain reaction (PCR) is used for the diagnosis of single gene defects such as cystic fibrosis, screening of specific diagnosis of X-linked diseases and the triplet repeats disorders such as myotonic dystrophy. For PGD patients, especially those carrying fragile X syndrome, a test of ovarian reserve is recommended. The embryo biopsies discussed in this chapter are: polar body biopsy, cleavage stage biopsy, blastocyst biopsy. The chapter lists out single gene disorders for which successful PGD protocols have been reported. Fluorescent in situ hybridization (FISH) determines the number of copies of a particular chromosome or region of a chromosome when it is difficult or impossible to obtain good quality metaphase preparations.