what is genetic testing?

Genetic Testing

We offer 2 different genetic tests: Carrier Screening for single gene mutations and Preimplantation Genetic Testing of embryos.

A tiny baby's hand resting on a parents hand.

Understanding Genetic Testing

the poma difference

We make sure that carrier screening occurs in the same laboratory for both partners because the genetics laboratories will then provide PGT-M testing for a nominal fee.

Many clinics recommend PGT biopsy and freezing all the embryos to allow a frozen embryo transfer of a euploid (normal) embryo. We offer this policy as well, but we also offer transfer of a fresh untested embryo is not any riskier than a natural or IUI conception and prevents having to wait for a frozen embryo transfer with the necessary delay and potential cost increase of a frozen cycle.

We use a laboratory, Genomic Predictions Laboratory, that uses technology to minimize the diagnosis of mosaic embryos, which can create challenges regarding the decision of which embryo to transfer.

Carrier screening refers to a blood test to determine if the sperm and egg both contain a single gene mutation, called autosomal recessive. When the sperm and the egg both carry the same autosomal recessive gene mutation, the resulting child has a 25% chance of disease. Carrier screening allows usto identify carriers and use PGT technology to diagnose disease in embryos which then permits us to transfer only unaffected or carrier embryos andprevent disease transmission.

Preimplantation Genetic Testing (PGT) is a technique for removing a few cells from an embryo to allow testing for genetic abnormalities. PGT comes in 3 forms: PGT-A (aneuploidy) evaluates the number of chromosomes and an embryo; PGT-M (mutation) evaluates the embryo for an autosoma lrecessive disease (predicted by carrier screening); and PGT-SR (structural rearrangement) evaluates chromosomes that have structural changes such as a translocation. PGT-A is the most common technique used to identify embryos that have the normal number of chromosomes and provide the highest probability of a successful implantation and pregnancy.

To learn more about working with POMA Fertility, please schedule your consultation today, or give us a call at 425.822.7662

FAQ's

PGT biopsy removes a few cells from an embryo for analysis. Most PGT determines the number of chromosomes present in each cell (PGT-A for Aneuploidy). A normal embryo has 2 complete sets of chromosomes (one set from the female and one set from the male, called euploid). If the embryo contains the incorrect number of chromosomes, then it usually fails to implant, results in a miscarriage or results in an abnormal child such as Downs syndrome. Euploid embryos have the best chance of implantation and delivery of a liveborn child.

Why perform PGT?

expand

The goal with IVF treatment is to transfer a single embryo resulting in a single healthy birth. Excellent quality research shows euploid embryos increase the probability that the embryo will implant and continue to a live-born pregnancy. PGT also reduces the miscarriage rate by about 50%. PGT research showed that compared to choosing the embryo for transfer based on the morphology (appearance) alone, PGT changed the embryo choice about 15% of the time for women <35 years old and 30% of the time for women 35 years and older. PGT gives patients the confidence to continue single embryo transfer and deliver the healthiest baby possible. PGT can also shorten the time to delivery by efficiently transferring the correct embryo.

Is PGT accurate?

expand

PGT euploid status is about 99.5% accurate and PGT aneuploid status (abnormal embryos) is about 97% accurate. False abnormal rate is 2-3%. Some physicians and researchers debate the exact accuracy but very research suggest these numbers are correct.

Can all embryos be biopsied for PGT?

expand

PGT biopsy requires embryo culture until Day 5/6 because embryo biopsy on Day 3 results in a 40% lower implantation rate, but biopsy on Day 5 or 6 does not decrease the implantation potential of the embryo. However, not all blastocyst embryos have enough cells to biopsy them without harming their viability. Assuming all the eggs retrieved = 100% of the eggs for that cycle, about 78-80% of the eggs are mature, about 75-80% of mature eggs fertilize normally into zygotes (1-cell embryos) and about 49-51% of them develop into blastocysts. Combining these statistics yields 78-80% x 75-80% x 49-51% = 29-33% of retrieved eggs become usable blastocyst embryos. Our program estimates that about 75% of patients who desire PGT biopsy will achieve at least 1 embryo for biopsy.

Should everyone have PGT for their IVF cycle?

expand

In theory, YES – we should screen all embryos to choose the best embryo for transfer. However, cost, fear of embryo damage, ethical perspectives and miscellaneous other reasons lead patients to decline testing. PGT does not increase the overall success rate for the cycle. For example, if you have 5 embryos and we eventually transfer them all (not in a single transfer), then with or without PGT, you should have the same number of babies.