We recently found out that our clinic now offers microarray Comparative Genomic Hybridization (CGH) testing or sometimes called Comprehensive Chromosome Screening (CCS). This is the newer and better technology to in situ hybridization (FISH), that is commonly referred to as traditional Preimplanation Genetic Diagnosis (PGD). My clinic does the biopsy and then sends it to Reprogenetics in New Jersey for the actual testing.
What is CGH?
CCS is very advanced chromosome screening for embryos. It determines whether or not the embryos are normal, allowing you to pick the best ones for transfer. Abnormal embryos (Aneuploidy) are the cause of more than 60% of miscarriages. In the normal course of IVF, embryos are graded just by looking at them under the microscope, however abnormal embryos often look just like normal embryos. What this means to me, is that microscopic embryo grading is pretty much useless and means that you’re flying blind when picking the embryos. Therefore, CCS can help you increase your chance for pregnancy and live birth.
My doctor and embryologist both think that sometime in the future, this type of testing will be used in most all IVF cycles and will become standard.
It is a great option for:
- women who are 35 or older
- women with a history of repeated miscarriages
- women with a previous pregnancy involving a chromosomal abnormality
- women who have multiple failed IVF cycles
CGH vs. FISH (PGD)
|What is tested?||Chromosomes?||Average Cost|
|CCS||5-10 cells of Day 5 Blastocyst||23 pairs of chromosomes (all)||$4000-$6000|
|PGD||1-2 cells of Day 3 Embryo||5-11 chromosomes||$3500|
Advantages of CGH
Ability to Pick the Best Embryos: For women 35 and older with day 5 transfers, 1 out of every 3 embryos are aneuploid (abnormal). After embryo grading using the microscope, a decision is made on which embryos to use. After CCS, usually that decision changes in 40% of cases. To me, this is staggering. For example, a friend of mine had a perfect looking 5AA embryo that they would have transferred. Then, they did CCS testing and discovered that that embryo was abnormal with a trisomy 18, changing their decision on which embryos to transfer. (See examples of results here and here.)
Tests all chromosomes: There’s a lot less chance for error when more cells are tested and every chromosome is looked at. FISH testing has a chance for false negatives, while CCS is more accurate.
Less Damage to Embryo: Biopsying the embryo at a more advanced cell stage dramatically increases the accuracy of this testing and minimizes potential damage that the biopsy can cause on the embryo because it has several hundred cells by then.
Better Chance for Singleton Pregnancy: CCS gives doctors the knowledge that they are transferring the most chromosomally fit embryo, therefore precluding the need to transfer multiple, unscreened embryos in the hope that one will be healthy enough to create a pregnancy and a healthy baby. Pregnancy rates are the same for transferring one CCS-tested embryo vs. two non-tested embryos.
Disadvantages of CGH
The only disadvantage as far as I can tell is that you must have day-5 blastocysts to utilize this technology. For some couples, I imagine this is problematic. Also, I think you would probably want to have at least 4 embryos to test to make it worthwhile.
Also, the embryos must be frozen because the embryos can’t survive outside the body to Day 7 to wait for the results of the testing. So, they are flash frozen using vitrification, which is the newer and better method to traditional cryopreservation. Cryo usually has about 65-75% survival rate with about 50% cell loss. Vitrification has 90% survival rate with almost no cell loss. Because of the new freezing technology used, we didn’t feel that this was much of a disadvantage.
- Egg Retrieval
- Fertilization using ICSI which is necessary to prevent contamination with residual sperm adhered to the egg when they do the biopsy.
- Embryos grow in the lab
- On Day 5, hopefully there are embryos remaining and then the biopsy is done.
- The biopsies are transported to the lab in New Jersey and then vitirified at our lab.
- Results in two days from the lab, pick embryos
- Ready for a frozen transfer for our gestational surrogate
Why we decided to do CGH Testing
Ultimately, we decided to do the testing because we don’t want to have any regrets and because some doors opened for us with the costs. Even though we have every reason to believe that the problem lies with my body, we really have no proof that our embryos are healthy. They look good under the microscope, but that doesn’t necessarily mean anything. We are solving the problem with my body by using a gestational surrogate, but we also want to guard against any possible problems with the embryos by doing this testing. We just can’t keep going and don’t have the emotional energy to not give ourselves the best chance possible right now. After 7 years, 6 IVFs and 5 miscarriages…this is it! We have to go all out and not hold back.
I stressed about the price of another $4200 on top of everything else, but luckily for me, several amazing things happened on the day we needed to decide: 1. I have a great friend from a support group that gave me a generous gift to help with the costs and I was shocked and amazed by her kindness. 2. I settled an insurance claim with Chipotle. 3. I sold my old camera. I felt that God was answering prayer with the confluence of these events and that we should go for it. These things cut the cost in half for us. If money were no issue, then we would have had nothing to consider as we’d jump at the chance to use this testing.
CGH will give me better peace of mind that if we get pregnant, we would have a higher chance of a normal baby. I have been really worried about birth defects ever since hearing my friend’s results — that she had a perfect embryo they were going to use and then testing revealed it to be a Trisomy 18. I also have another friend in her second trimester with a Trisomy 18 baby. So, birth defects are on my radar. I admit that there is NO reason to think this would be a problem for us, but after the incredibly difficult journey we’ve had, we just want to be extra careful and give ourselves the best possible outcome.
The biggest downside for me is that I will need more aggressive treatment to get enough eggs to be able to make enough 5-day embryos. Even when I’m treated conservatively, I get OHSS. So, this means that I will most likely get a really bad case of OHSS, which I’m not looking forward to. But, why stop now? After everything we’ve been through. This is it — all in!
We want to eliminate any possible problems because we want no regrets, less stress in worrying about it and because this is it for us.
Who else has done this testing or thought about it?