Preimplantation Genetic Testing

Air Date: 5/25/16
Duration: 10 Minutes
Preimplantation Genetic Testing
Preimplantation genetic diagnosis (PGD) allows for the detection of life-altering genetic abnormalities prior to embryo transfer during IVF.

The procedure can also help patients suffering from certain fertility challenges as well.

The PGD procedure is an evaluation of chromosomes, thread-like structures found in all human cells except red blood cells.

The PGD process starts after the embryo is fertilized and allowed to grow, when an embryo biopsy is performed.

This procedure involves removing either a polar body, which is half of the maternal DNA, or a blastomere, which is a cell from the embryo that contains its DNA.

Alan Martinez, MD, is here to help you better understand Preimplantation genetic testing to identify genetic defects in embryos created through in vitro fertilization (IVF) before pregnancy.

Transcription:

Melanie Cole (Host): Pre-implantation Genetic Diagnosis, or PGD, allows for the detection of life-altering genetic abnormalities prior to embryo transfer during IVF. The procedure can also help patients suffering from certain fertility challenges as well. My guest today is Dr. Alan Martinez. He's a specialist in reproductive endocrinology and infertility at the Reproductive Science Center of New Jersey. Welcome to the show, Dr. Martinez. So, tell us a little bit about PGD and what that is and who is this procedure for?

Dr. Alan Martinez (Guest): Okay. Hello. Thank you for having me on today. PGD stands for “Pre-implantation Genetic Diagnosis” or testing and it is usually performed in patients undergoing in-vitro fertilization where you are generating embryos for the purposes of trying to conceive and then testing those embryos to check them for either a specific mutation or either abnormal chromosome number.

Melanie: So, what is it you're looking for with this procedure?

Dr. Martinez: Well, in many of our infertile patients, a major reason for miscarriages, even at a relatively young female age, as well as in older female patients and older males, is they may actually have either egg or sperm that may have some genetic abnormalities. So, in the instance of pre-implantation genetic screening, we're taking a few cells out of an embryo that is about day 5 of embryo life, and we are testing them to check and see if they have a normal chromosome number. The idea is that we're to rule out such things as chromosomal problems such as Down Syndrome or trisomy 21. We can detect conditions like that and then potentially screen out healthy embryos to use to try to get people pregnant. The ultimate means, the reason why we do this, is to decrease the miscarriage rate and the non-conception rates in these individuals.

Melanie: Is there any risk to the embryo?

Dr. Martinez: At that point and stage, the embryo is advanced, you're working with very high-quality embryos, so the risk to the embryo is minimal. It does require a highly-specialized lab and we work with a group of individuals who perform this. The expertise is very important, but the embryo itself is, it is a technical, but in the right hands, this procedure has a very high success rate with minimal to no damage to the embryo.

Melanie: Dr. Martinez, if an embryo has gone through this test and then it's implanted, does then the woman need any further testing for genetic abnormalities or do you then know and there's no more stress for that nine months?

Dr. Martinez: That is a very good question. I think we can alleviate some of the stress in knowing the embryo has already gone through one set of rigorous tests, but like anything else, nothing is 100% foolproof. So, patients still are recommended to have their normal screening and their testing that would be done in the first trimester of pregnancy to potentially look for any abnormalities that may have not been found by this test and it's still important to undergo that testing.

Melanie: So, is this something that's included in normally? Or is this some specific thing that you discuss with the patient that's only required in some circumstances?

Dr. Martinez: That's a very good question. In our entire infertility consult, when we discuss in vitro fertilization, we look at the fertility diagnosis, we look at the age of the patients, and we discuss with them their likelihood of generating an egg or sperm that may have some chromosomal abnormalities. And we can gauge this based on, primarily, the maternal age. If a patient is in her early 30’s or less than 35, the miscarriage risk is relatively low. As you get into your mid- to late 30s, 37, 38, the ovaries start to age at a greater rate, so this counseling and this testing become more recommended, especially in an older female population, because their risks of having an abnormal chromosome embryo increases as you progress in age. There is also something called “pre-implantation genetic diagnosis” and that is when either the female or male partner has a known genetic mutation such as say, Marfan Syndrome, where you may know that there's a specific gene which is affected in that individual. We can take these embryos and not only screen them for their chromosome number, but we can screen them to potentially decrease the chances that an embryo would have that same disease as the mom or the dad.

Melanie: So, what would you like people to know about asking for this type of test or getting involved in this procedure if they're looking at IVF?

Dr. Martinez: Well, I think they need to, first of all, talk to a specialist such as myself and we look at their infertility history. Patients that are good candidates or excellent candidates for this are those that may have conceived in the past but they had recurrent miscarriages, so maybe there's a genetic component that we're looking to uncover. And, in those cases, we may discuss that more seriously with those patients. I think that being aware that the technology exists; counseling the patients and giving the patients the options of selecting this additional test which may lead to increased pregnancy rates, that is a consideration for a woman of any age, and then it's up to the individual whether they want to proceed with the testing.

Melanie: How do you discuss the results and what if the results are not great? What do you say to the patient?

Dr. Martinez: Well, if the results show us that there are abnormal embryos, that is exactly the reason why we did the test in the first place, because you can look at an embryo in the laboratory setting, which looks completely normal, externally, but then when you biopsy two or three of those same embryos which are Grade-A quality and they look perfect, well, only one of them or none of them may be chromosomally normal. And then, we know in those cases, we would not use those embryos. We would not transfer them back in because the likelihood of conceiving from those is very, very low. And so, when we do receive a positive result or an abnormal test, that's the whole reason why you set forth to proceed with this testing. And the patients, if they're counseled, they're prepared for that and they understand that that's a possibility.

Melanie: That's absolutely fascinating, what you're able to do. Tell us about your team at the Reproductive Science Center of New Jersey.

Dr. Martinez: Well, at the Reproductive Science Center of New Jersey, we are a smaller practice, but we've been around for over 11 years, now. We offer a full range of fertility treatments from basic level all the way up to what we just discussed, IVF or Pre-implantation Genetic Testing. We offer our patients a personalized experience and we just want to make ourselves available to guide our patients through the process of this testing.

Melanie: Thank you so much, Dr. Martinez. It's fascinating information. You're listening to Fertility Talk with RSCNJ and for more information, you can go to fertilitynj.com. That's fertilitynj.com. This is Melanie Cole. Thanks so much for listening.