What Is Preimplantation Genetic Testing?

Preimplantation genetic testing is a bipartite process that allows an embryologist to sift through embryos created via IVF, for genetic defects. The system offers two diverse, revolutionary methods for testing. The first, is preimplantation genetic screening (PGS), a technique that evaluates embryos of chromosomally normal genetic parents for structural or numerical chromosomal errors. The second method is preimplantation genetic diagnosis (PGD), a tool that highlights anomalies in embryos whose parents have a known history of genetic abnormalities. PGD can uncover sex-linked disorders, single gene defects and chromosomal disorders.

Why Choose Preimplantation Genetic Testing?

Preimplantation genetic testing tools present several advantages for hopeful parents, promoting only healthy embryos that are likely to succeed.

Is Preimplantation Genetic Testing Right for Me?

Preimplantation genetic testing is suited for couples where one or both partners are carriers of sex-linked disorders or genetic or chromosomal abnormalities. The procedure is also useful for women who are over 35 years old, or those who have experienced failed fertility treatments or recurrent miscarriages.

What Are the Steps of Preimplantation Genetic Testing?

Preimplantation genetic diagnosis (PGD) and preimplantation genetic screening (PGS) are parallel procedures that follow similar steps.

  • 1Cell Retrieval

    First, a pair of cells is extracted from each multi-cell embryo.

  • 2Cell Evaluation

    Once several pairs of cells are gathered, each set is examined to gauge the potential presence of an abnormal gene in the corresponding embryo.

  • 3 Embryo Transfer

    Following the selection of the best embryos from the cell evaluation routine, your embryologist will transfer up to two embryos to your uterus for implantation.

  • 4 Cryopreservation of Additional Embryos

    There are often embryos left over after embryos are transferred to the uterus. On Cloudnine, we offer advanced cryopreservation facilities that allow you to freeze your surplus embryos for use in future in vitro fertilisation (IVF) cycles. Cryopreserved embryos can be used for up to ten years.

What Are the Risks of Preimplantation Genetic Testing?

Genetic testing can prove to be inaccurate if inadequate attention to detail is given. The specialist team on Cloudnine aims to maximise the success rate of genetic screening and diagnosis by carefully engineering every step of the process.


PGS, or preimplantation genetic screening, is a genetic test performed on embryos produced through IVF. PGS gives information about embryos' genetic health to help your fertility specialist to select the best embryo for transfer and improve your chance of achieving a successful pregnancy. PGS identifies embryos with the correct number of chromosomes, so your care team can select the embryo with the best chance of leading to IVF success. Cloudnine uses the most advanced embryo screening technology available, to provide a complete picture of chromosomal health.


For people who know they are at increased risk of passing on a specific genetic condition, PGD, or preimplantation genetic diagnosis, can be performed prior to pregnancy to greatly reduce the risk of having an affected child. PGD for single gene disorders involves testing embryos created through in vitro fertilization (IVF) and then transferring unaffected embryos. Each PGD test is unique and DNA samples from both the partners are tested. Then, linkage analysis is used to determine the 'genetic fingerprint' of the mutation and diagnose each tested embryo as affected or unaffected