Pre - Before
Implantation - Process of embryo sticking to inner layer of uterus - endometrium
Genetic - Study of genetic constitution of embryo
Diagnosis - Diagnosis
Pre-implantation genetic diagnosis - PGD is a latest technique, which has revolutionized the possibility of diagnosing genetic disorders of the child to be born BEFORE even the pregnancy actually begins. PGD is a blessing for the patients who are likely to have a child affected by a known genetic disorder or when possibility of a child being born with genetic abnormality is high.
Medical sciences has discovered that many diseases are caused by faulty genes. Defect in genes in the parents can be transmitted to their children and the child may be born with the disease. Some gene defects may not be present in the parents but develop during the process of fertilization.
If we do biopsy of an embryo and take out one or two cells ( blastomeres ) from the embryo and study the genetic constitution of the embryo we can diagnose, whether the embryo is having normal genes or has gene defect and how much is the possibility of the child being affected by the disease.
IVF + ICSI is done in the usual manner. Three days after ovum pickup and fertilization, embryo biopsy is planned. Assisted hatching is done on the embryo to be biopsied. ( To understand Assisted hatching please see Assisted hatching section for more details). A blunt embryo biopsy pipette is taken to the embryo. A gentle suction is applied on one, blastomere to take it out from the embryo. One or two blasomeres are removed from each embryo to be examined. Aspirated blastomeres are fixed by specialized technique.
The biopsied blastomeres are processed by two different techniques.
Fluroscent In Situ Hybridization - FISH
This is very fast technique and gives result within 24 hours.
- Advantages of FISH :
It gives fast results.
Very useful for numerical anomaly diagnosis.
- Disadvantages of FISH :
It does not detect structural anomalies of genes.
Polymerase chain reaction - PCR
It multiplies the genes many times and then does the study for abnormality.
- Advantages of PCR :
Gives more accurate diagnosis as number of genes available for study are more.
Better for detection of minor defects.
- Disadvantages of PCR :
Takes more time 2 to 3 days
Who can benefit from PGD ?
Couples with known diseases which can be transmitted to the children born.
Couples where family has a history of birth of a child affected by a disease which can be transmitted in other children also.
Couples in which the chances of genetic defects are more in children born.
Advanced age of partners.
History of multiple unexplained abortions.
Multiple IVF cycle failure.
Very few centers across the glob and India have PGD facility.
Bavishi Fertility Institute is the first and the only ART clinic in 'Gujarat state and Western India ' (Except Mumbai) to have PGD facility.
Because of the in-house facility for PGD, it is surprisingly affordable too !!