The PGD Process Step by Step

By BSc, MSc (embryologist) and BA, MA (fertility counselor).
Last Update: 05/30/2014

To perform a Preimplantation Genetic Diagnosis (PGD), it is necessary to use a cell from each embryo obtained with a cycle of in vitro fertilisation or ICSI.

Below you have an index with the 4 points we are going to deal with in this article.

When is it performed?

Three days after follicular puncture and egg fertilisation by a spermatozoon, that is to say, when the embryo has divided into 6-8 cells, the PGD is performed.

Firstly, a hole is made in the pellucid zone (a.k.a. egg coat) using a laser or using hyaluronidase from the embryo, and then the cell or blastomere is aspirated.

Chromosomal analysis

After that, a chromosomal analysis of the cell is performed at the genetics laboratory by means of a technique called FISH or with microarrays, a technique which allows a massive analysis of genetic disorders.

PGD is a complex technique used by expert biologists.

Does it harm the embryo?

At this early stage of embryo development, its cells are totipotent stem cells, that is to say, they can differentiate into any cell in the human body until a whole organism is developed.

Thus, performing a biopsy on a cell from the embryo won't cause any problem on its development, which will finish when a whole human being is formed.

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 Neus Ferrando Gilabert
Neus Ferrando Gilabert
BSc, MSc
Bachelor's Degree in Biology from the University of Valencia (UV). Postgraduate Course in Biotechnology of Human Assisted Reproduction from the Miguel Hernández University of Elche (UMH). Experience managing Embryology and Andrology Labs at Centro Médico Manzanera (Logroño, Spain). More information about Neus Ferrando Gilabert
Adapted into english by:
 Sandra Fernández
Sandra Fernández
Fertility Counselor
Bachelor of Arts in Translation and Interpreting (English, Spanish, Catalan, German) from the University of Valencia (UV) and Heriot-Watt University, Riccarton Campus (Edinburgh, UK). Postgraduate Course in Legal Translation from the University of Valencia. Specialist in Medical Translation, with several years of experience in the field of Assisted Reproduction. More information about Sandra Fernández

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