Patient: Dr. Malpani, I’ve heard a lot about genetic testing in IVF. We know that one of the main reasons for IVF failure is a genetic defect in the embryo, so shouldn't we be testing embryos for genetic abnormalities before transfer?
Dr. Malpani: That’s a common question, and on the surface, it does seem like a logical step. You’re right that the success rate of IVF is not 100%, and the most common reason an embryo doesn’t implant is often a genetic defect. The idea of testing embryos and only transferring the genetically normal ones sounds straightforward, but it’s not that simple.
Patient: Why not? Isn’t genetic testing of embryos a way to ensure a higher chance of success?
Dr. Malpani: It might seem so, but there are limitations. We do have the technology to test embryos through a process called preimplantation genetic diagnosis (PGD) or preimplantation genetic testing (PGT). However, the term "genetic testing" can be misleading. What we can actually test for is the number of chromosomes in the embryo. We can conduct what's called aneuploidy screening or chromosomal testing, but it’s impossible to test for all 30,000 genes in the embryo.
Patient: So, you're saying we can't detect all possible genetic issues?
Dr. Malpani: Exactly. When we do an embryo biopsy, we remove just two or three cells from a 100-cell embryo. There are major limitations to this technology. It only allows us to screen for chromosomal abnormalities, not for every potential genetic defect. Patients often have unrealistic expectations. Even if an embryo appears to have a normal number of chromosomes, that doesn’t guarantee that all other genes are normal.
Patient: So, does this mean even after genetic testing, there's still a risk of miscarriage?
Dr. Malpani: Yes, the miscarriage rate after transferring a "PGD normal" embryo is nearly the same as it would be if you hadn't done the genetic testing at all. Just because an embryo is euploid (has a normal number of chromosomes) doesn't mean it is free from other genetic defects that could affect the outcome. In some cases, you might still end up with a miscarriage or an IVF failure despite undergoing genetic testing.
Patient: That’s quite disheartening. So, what’s your advice regarding genetic testing?
Dr. Malpani: My advice is to be cautious. Don’t throw your money away on genetic tests or PGD without fully understanding their limitations. Genetic testing does not guarantee improved success rates. In some cases, it might be useful, but it’s not a foolproof method to ensure pregnancy success.
Patient: I see. It seems like this requires careful consideration.
Dr. Malpani: Absolutely. It's important to have realistic expectations and make informed decisions about your IVF treatment.