Preimplantation genetic diagnosis (PGD) refers to testing that is performed on embryos prior to implantation or on oocytes prior fertilization. PGD testing is used to detect problems with specific genes or chromosomes in embryos. As an alternative to prenatal diagnosis and possible termination of pregnancy of an affected fetus for couples who are at risk of passing on serious genetic diseases to their children.

Preimplantation genetic diagnosis technique requires the use to thest embryos for genetic disorders before it implants in the womb. It offers the couple at risk the chance to have an unaffected child and avoid the need for abortion.

To whom PGD is advised?

• Women of advanced maternal age (over 35)
• Couples with recurrent miscarriages
• Couples who have experienced several failed IVF cycles
• Couples who have had a prior pregnancy with a chromosome abnormality
• Men with infertility requiring intracytoplasmic sperm injection (ICSI)
• Men with positive aneuploidy sperm screening
• Couples with at least one partner is has aneuploidy mocaicism
• Couples where at least on partner is a carrier of an X-linked disease
• Couples where at least one partner is a carrier of structural chromosomal rearrangement

Reasons for using PGD:

• PGD for single gene mutations
• PGD for determination of chromosome number (aneuploidy)
• PGD for structural chromosome abnormalities (translocations)
• PGD for Tissue Typing
• PGD for Gender Selection

 Single Gene Defects or HLA Matching

To develop a test for a single gene defect (e.g. Cystic Fibrosis, Marfan Syndrome, Sickle Cell) and HLA matching, we use a technique that combines genetic linkage testing with traditional mutation analysis. Test development can take up to 6 months and will require blood samples from you and your partner and, possibly, additional family members. When test development has been completed, testing of the embryo can take place

Chromosome Imbalance in Translocation Carriers

Test development for chromosomal rearrangements takes from 4-8 weeks and will require
blood samples from you and your partner and, possibly, additional family members. When
test development has been completed, testing of the embryo can take place. If a test was
developed for you more than 6 months ago, it will need to be validated prior to starting your
fertility treatment. For men with a chromosome rearrangement, a sperm translocation test is
recommended to identify the proportion of sperm present with an unbalanced form of the
translocation in a semen sample.

Aneuploidy

Aneuploidy screening is a procedure that screens for the number of chromosomes present in
an embryo. By screening embryos and only transferring those with no identifiable genetic
abnormalities, we aim to reduce the risk of having a child with a chromosome abnormality,
reduce the risk of miscarriage and provide useful diagnostic information regarding the
likelihood of success through IVF treatment.