Investigation into the incidence and origin of segmental aneuploidies
Research type
Research Study
Full title
Investigation into the incidence and origin of segmental aneuploidies in human preimplantation embryos using PGTai2+ platform
IRAS ID
294909
Contact name
Darren Griffin
Contact email
Sponsor organisation
London Womens Clinic
Clinicaltrials.gov Identifier
N/A, N/A
Duration of Study in the UK
3 years, 6 months, 14 days
Research summary
The aim of in-vitro fertilization treatment is usually to achieve a healthy singleton birth. There are many reasons why this is not always achieved but numerical chromosomal abnormalities in the embryo (aneuploidy) are believed to be the main causal reason behind failure of treatment in couples with unexplained infertility, multiple miscarriages, or affected live birth. Aneuploidy can arise from either paternal or maternal gametes or post-fertilization events. In recent years, accurate techniques for the detection of aneuploidy have been developed. Research using such methods has confirmed that aneuploidy is a common feature of human oocytes and preimplantation embryos. However, thus far research has mainly focused on loss or gain of whole chromosomes. Despite next-generation sequencing, which now allows for the accurate detection of segmental aneuploidies (i.e. not involving the whole chromosome) from in vitro fertilization embryo biopsies, the origins and characteristics of these aneuploidies are still relatively unknown.
The purpose of this study therefore is to provide a service evaluation offered at the London Women’s Clinic (LWC) by comparing an older technology, ‘PGTai2’ with an enhanced approach termed the ‘PGTai2+’ which provides more information as to the nature and origin of any detected chromosomal abnormalities. This will enable the investigation of whether previously diagnosed segmental aneuploidies found in human preimplantation embryo biopsies have their origin in the eggs or sperm or whether they mostly arose after fertilisation. It will also investigate if there are clinical correlations between paternal age, semen parameters and severe male factors on these segmental aneuploidies or whether they may have been introduced by the biopsy procedure. To investigate this, genetically abnormal, non viable embryos stored at LWC which have already been donated for research before being discarded will be further analysed by several biopsies of 5-7 cells. We will apply a new, gentler technique to re-biopsy embryos that were discarded from clinical use after earlier biopsy had shown them to be chromosomally abnormal, and use the new test to re-assess the chromosomes in a more informative way. Using DNA obtained from the parents by a mouth swab, we will be able to determine whether any error was already present in the egg or sperm or arose in the embryo after fertilization. Reanalysis of the original traces using the new technology (AI algorithm) will provide insight into differentiating between these two.REC name
London - Surrey Borders Research Ethics Committee
REC reference
21/LO/0237
Date of REC Opinion
11 May 2021
REC opinion
Further Information Favourable Opinion