Pre-Implantation Genetic Diagnosis (PGD)
What is PGD?
Pre-Implantation Genetic Diagnosis (PGD) is a reproductive technology used during in vitro fertilization (IVF) to screen embryos for genetic disorders or chromosomal abnormalities before they are implanted in the uterus. PGD is used primarily to help couples at risk of passing on genetic conditions to their offspring or to improve the chances of a successful pregnancy in IVF cycles.
Should I Go For PGD?
You should certainly choose PGD as a precaution if –
- You have had multiple abortions due to genetic conditions.
- You have had a child with serious genetic conditions.
- You have had a family medical history of serious genetic disorders.
- You are fearful of a genetic condition affecting your baby.
How Does PGD Work?
- IVF Procedure: The process begins with IVF, where a woman’s eggs are collected and fertilized in the laboratory with sperm. This results in the creation of several embryos.
- Genetic Testing: After a few days of embryo development, typically at the blastocyst stage (around 5-7 days after fertilization), a small number of cells are removed from each embryo. These cells are then subjected to genetic testing.
- Genetic Analysis: The genetic material (usually DNA) from the removed cells is analyzed to identify specific genetic disorders or chromosomal abnormalities, such as Down syndrome or cystic fibrosis. The most common techniques used for PGD include polymerase chain reaction (PCR) for specific gene mutations and fluorescence in situ hybridization (FISH) or array comparative genomic hybridization (aCGH) for chromosomal abnormalities.
- Selection of Healthy Embryos: Based on the genetic analysis, embryos free from the identified genetic conditions are selected for transfer into the woman’s uterus. This increases the likelihood of having a healthy pregnancy and reducing the risk of passing on a genetic disorder to the child.
PGD is often recommended in situations where one or both parents have known genetic conditions that they want to avoid passing on to their offspring. It can also be used for family balancing or to select embryos with a tissue type that can be a match for a sibling with a specific medical condition, such as a bone marrow transplant.
It’s important to note that PGD is a specialized procedure typically performed at specialized fertility clinics with expertise in genetic testing and counseling. It allows for the identification and selection of embryos free from specific genetic diseases or abnormalities but does not guarantee the success of the IVF cycle or a healthy pregnancy. It is essential to consult with a fertility specialist and a genetic counselor to determine if PGD is appropriate for your specific situation and to discuss the potential benefits and limitations of the procedure.