Chromosomal Screening of Embryos Preimplantation genetic testing is an investigation conducted in order to check for genetically normal embryos. This investigation can be performed on embryos prior to embryo transfer during IVF. Genetic testing is a vital resource for many couples, especially those with known family history of genetic defects.
There are two types of Preimplantation genetic test:
- Preimplantation Genetic Diagnosis (PGD) – This test is performed to identify which embryo is affected by specific genetic defect. This test is performed only when parents carry any specific genetic defect. PGD is used to test for any genetic defect that is known to be caused by any specific gene.
- Preimplantation Genetic Screening (PGS) – PGS test is used to detect any abnormality in the number and structure of the chromosome of an embryo. The process is also called aneuploidy screening. PGS improves the chance of getting pregnant and continue pregnancy without any hassle. It also reduces the chance of having a baby with a condition like Down syndrome or any other chromosomal disorder.
PGS/PGD techniques
Who can benefit from PGD and PGS?
- Couples with family history of genetic disorders or chromosome problems
- Couples having a child with serious genetic condition
- Severe male infertility
- Women diagnosed with unexplained infertility
- Ageing mother
- Couples who carry a gene for a sex-linked disease such as haemophilia
- Women with two or more miscarriages (recurrent miscarriage)
- Women who have undergone numerous unsuccessful fertility treatment(IVF)
PGD versus PGS
| PGD | PGS |
| Involves detection of genetic disorders in embryo | Involves detection number and structure in the chromosome of embryo |
| This test is performed for people having a history of miscarriages or failed infertility treatment | This test is done when couples are carriers of a genetic disorder. |
Benefits of PGD and PGS are
- It helps early detection of chromosomal or genetic problems before the embryo is transferred into uterus.
- It increases the chance of conceiving a healthy child.
- It allows older women to still have viable children.
- Reduced risk of passing a genetic defect to a child.
If a couple has a family history of genetic defects or there are chances of chromosomal abnormalities, they should consult well qualified and certified infertility specialist to address their concerns and option to deliver a healthy baby.