Lab tests (genetics)

Dr Prem Demo3 offers two vital lab tests Pre-implantation Genetic Diagnosis (PGD) and Pre-genetic Screening PGS for intended couples. Many childless couples opt for this high-precision screening tests mainly to rule out any genetic abnormalities in the embryo created through IVF. Couples having a child with a genetic disorder may consider PGD in IVF.

Many times, a couple intends to have a child of a specific gender to maintain gender balance in the family or to prevent a genetic disorder. However, many countries do not legally permit PGD beyond any serious medical necessity.  Ukraine allows PGD regulated by the order of the Ministry of Health.

One thing is to be noted that PGD cannot guarantee 100% genetically healthy embryos. Of 4000 single gene disorders, PGD can help in ruling out the possibility of only a few namely Myotonic Dystrophy, Cystic Fibrosis, Thalassemia, Fragile X and Tay Sachs.

Difference between PGD & PGS

These are two different tests that may be required before implanting the embryo created from IVF into the uterine cavity. These tests are purposed for different reasons and may not be mandatory for specific couples.

PGD, a diagnostic genetic test, helps in choosing the best embryo for implantation among few others created through IVF. It tests to determine whether a specific genetic disorder is present in one or all embryos and choose the one having the highest chances of survival and the least chances of the disorder.

PGS is also an embryo-screening test but it identifies chromosomal abnormalities. If the embryo has lesser or more number of chromosomes, chances are there that the embryo will not survive. Even if t survives, it may carry some severe genetic disorders like Down’s syndrome.

Who needs PGD and PGS?

PGD – Couples with a higher risk of carrying specific genetic disease that can be transmitted to the fetus can opt for PGD. Even if both the spouses/partners do not actually have a genetic disease but are its carriers can take this test to rule out the risk of transmission to the embryo.

PGS- Women with a history of miscarriages planning for IVF can take this test. It will help in detecting the chromosomal abnormality in a specific embryo before implantation making a big difference in the success of IVF.

Recommendation for PGS:

  • Women above 38 years of old opting for single embryo transfer
  • Women with more than 2 incidences of miscarriage
  • Women with more than 2 incidences of IVF failure

Techniques followed in PGD

Fluorescent in situ hybridization (FISH) and Polymerase Chain Reaction (PCR) are two common techniques used in PGD. FISH is applied to detect chromosomal abnormalities as in PGS while PCR is applied to detect monogenic disorders.

Additionally, single cell genome sequencing is also used in PGD that leads to complete genome sequencing of the embryo.

Success rate with PGD

As mentioned, PGD is a high-precision test demanding the best level of expertise. The success rate of PGD in Dr Prem Demo3 is remarkable as we take careful measures in egg donor selection and in all the associated procedures. The donor has at least one instance of successful egg donation producing more than 10-15 eggs.

We check these criteria so that we can get many embryos for blastocyst culture and create disease-free embryos. However, PGD can only be done in the blastocyst phase where the embryo is just 5 day old. After PGD, the number of embryos may get reduced. Rarely, the intended couple is left with only one healthy embryo instead of several ones and the gender may not be the same as expected.

Risk factor with PGD and PGS

Accidental embryo damage

Experience and expertise matter. Thankfully, Dr Prem Demo3 is enriched in it. Both PGD and PGS need micro-manipulation and none but experienced embryologists can handle this well. The chance of accidental embryo damage during the cell removal process is very low. With our talented specialists in the job, we allow intended couples to be at mental peace during this time.

Hardly one or two cells are removed from the embryo that is yet to go through the development phase. It does not in any way affect the fetus or the baby-to-be. The process may delay the cell division for just a few hours but it will not hamper normal development as cell division gets restored soon.

Misdiagnosis

PGD normally gives 90% accurate results. The remaining 10% may be false negative or positive or no result. Cells originating from the same embryo should have similar chromosomal constituents. In a few cases, there may be some anomaly owing to misdiagnosis.