I'm the PP poster above. I'll give you a specific genetic example. My husband actually has cystic fibrosis. That means he carries two defective genes that code for a certain protein. People will only have CF if both copies of that gene are mutated. We had to do IVF for CF male infertility, but our first step was for me to get a genetic test. Our child will always inherit one mutated gene from my husband. As long as I'm not a carrier for CF (which, luckily I'm not), our children practically have zero risk of having CF. So no PGD was needed for us. If I were a gene carrier, then our children would have a 50% chance of inheriting my defective CF gene and would have the disease. So PGD would be used to make a tailor-made test to see if our embryos either inherited the healthy gene, or if they got the defective gene (thus having CF).

So in the example of what would've happened if I had been a carrier, we would probably end up with about ~50% of our embryos not having CF after PGD. Now, we would need to decide whether or not to do PGS to make sure we didn't have an extra or missing chromosome from those embryos. This would be an additional test and cost.

Anonymous wrote:

Anonymous wrote:PGS means screening embryos that is suitable for pregnancy and birth, it detects chrom abnormalities that results in miscarriage or down syndromes. PGS's goal is to tell whether the embryo will survive pregnancy.

PGD means diagnostics of genetic diseases that does not interfere with pregnancy and birth, but might be problem for baby and/or grownups. So PGD's goal is to tell what kind of person the embryo will become after birth. Gender selection is part of PGD because gender chrom detection has nothing to do with pregnancy and birth outlooks, but really look into what kind of person the embryo will become.

PP here, so conclusion would be, priority wise: PGS first, make sure a baby can be born and PGD next making sure baby doesn't have genetic defects.

If you have a reason to do PGD (i.e. you and your spouse have the genetics to have a child with a serious disease) that'd be first priority. But if you don't have that potential, PGD would never be done.

PGS is definitely optional. Most chromosomally abnormal embryos will either not implant, or the pregnancy will miscarry. Many doctors don't bother recommending it unless you are over 35 when doing IVF or have a history of miscarriage. I've done two cycles of IVF and never once had a doctor even mention PGS testing to me.

I disagree with the above statement that PGD is for gender selection. PGD is only looking for a very specific gene. PGS looks at chromosomes, which is how you're also able to find out the sex of the baby (is one of the chromosomes an X or Y). They're two entirely different tests.

Anonymous wrote:PGS means screening embryos that is suitable for pregnancy and birth, it detects chrom abnormalities that results in miscarriage or down syndromes. PGS's goal is to tell whether the embryo will survive pregnancy.

PGD means diagnostics of genetic diseases that does not interfere with pregnancy and birth, but might be problem for baby and/or grownups. So PGD's goal is to tell what kind of person the embryo will become after birth. Gender selection is part of PGD because gender chrom detection has nothing to do with pregnancy and birth outlooks, but really look into what kind of person the embryo will become.

PP here, so conclusion would be, priority wise: PGS first, make sure a baby can be born and PGD next making sure baby doesn't have genetic defects.

PGS means screening embryos that is suitable for pregnancy and birth, it detects chrom abnormalities that results in miscarriage or down syndromes. PGS's goal is to tell whether the embryo will survive pregnancy.

PGD means diagnostics of genetic diseases that does not interfere with pregnancy and birth, but might be problem for baby and/or grownups. So PGD's goal is to tell what kind of person the embryo will become after birth. Gender selection is part of PGD because gender chrom detection has nothing to do with pregnancy and birth outlooks, but really look into what kind of person the embryo will become.

Oh, I see. Thank you!

Yup! Only PGS. They need to specifically be looking for something for Pgd. You'd only have it done if you were a carrier and then, they'd only be looking for that specific gene. It's not like it's a broad test which tests for several disorders.

Sorry, I meant PGS. We checked for missing/extra chromosomes and I am not a carrier for anything lab can test with current technology (all negative). Do I just need PGS then?

I'm confused, are you a carrier for a dominate gene? Or are you confusing PGD and PGS? PGS is just looking at the # of chromosomes. So preventing things like Edwards and downs syndrome. Things that might cause a miscarriage or a major disorder. PGD will be done to specifically identify embryos that carry a certain genetic diseases such as cystic fibrosis.

I did the recessive gene carrier screening (Sema4) and everything came back negative. We still did PGD and about 50% of our embryos were abnormal. Do I need to do PGS as well? Is there any added benefit?