Ep 315: Making Designer Babies: The Truth About Genetic Testing

 Fertility Docs Uncensored is hosted by Dr. Carrie Bedient from the Fertility Center of Las Vegas, Dr. Susan Hudson from Texas Fertility Center, and Dr. Abby Eblen from Nashville Fertility Center. In this episode, we explore the various genetic tests available for infertility patients, including carrier screening, prenatal testing, and testing done during IVF. We discuss why these tests are important, what they detect, and how they can influence family planning decisions. We give you answers to many questions you may have. What is expanded carrier screening, and what types of traits does it look for in prospective parents? How does being a carrier for recessive traits affect a child, and what is the probability of a child being impacted if both parents carry the same trait? Which traits are typically tested, and why are only severe conditions included? How can results from carrier screening influence decisions about pursuing IVF and embryo selection? What is NIPT testing, and how is it performed during pregnancy? What types of chromosomal abnormalities can NIPT detect, and when is this testing appropriate? How is genetic testing performed at the time of IVF, and what are the different tests available for embryos? What is PGT-A, and how does it assess chromosomal abnormalities? How do PGT-M, PGT-SR, and PGT-P tests evaluate for recessive traits, structural abnormalities, and conditions caused by multiple genes? How do these tests help couples make informed decisions about their reproductive options? What are the advantages of testing embryos before implantation compared to testing during pregnancy? How can understanding these genetic testing options reduce risks and improve outcomes for patients undergoing fertility treatments? Knowing the answers to these questions will help you decide which of these tests are right for you. 

Transcript

Susan Hudson (00:01)

You're listening to the Fertility Docs Uncensored podcast, featuring insight on all things fertility from some of the top rated doctors around America. Whether you're struggling to conceive or just planning for your future family, we're here to guide you every step of the way.

Carrie Bedient MD (00:22)

Hello and welcome to another episode of Fertility Docs Uncensored. I am one of your hosts, Dr. Carrie Bedient from the Fertility Center of Las Vegas, and I am joined by my two preposterously pretty precocious.

Carrie Bedient MD (00:36)

I can read my own handwriting. Preposterously pretty, precocious, practically perfect in every way co-host Dr. Abby Eblen from Nashville Fertility Center and Dr. Susan Hudson from Texas Fertility Center.

Abby Eblen MD (00:45)

Hey everybody.

Susan Hudson MD (00:50)

I love practically perfect in every way because I tease my husband about that all the time because I'm five foot seven, which is moderately tall for a woman. I mean, it's not I'm not six two but seriously, and he's always harassed me about that I it was the minimal height requirement, which is actually pretty funny because with the exception of one person he dated all of his other girlfriends.

Abby Eblen MD (01:00)

I would agree with that.

Yes, so tell him I'm offended by that reference to being short. know, those of us that are five feet, five one, we can't help it.

Susan Hudson MD (01:27)

So I always give him a hard time whenever he's talking about my height. I'm like just practically perfect in every way.

Abby Eblen MD (01:33)

There you go.

Carrie Bedient MD (01:34)

So here's a question for you. Thinking about all of your prior partners before your spouse, did you have a type? Was there a height requirement? Was there a hair color, eye color requirement? Was there, and maybe it was not a distinct requirement at the time, but in retrospect, is there a pattern?

Susan Hudson MD (01:53)

Definitely a pattern.

Abby Eblen MD (01:53)

Yeah.

Carrie Bedient MD (01:54)

Alright, Susan, what's your pattern?

Susan Hudson MD (01:57)

Dark hair, blue eyes, tall. Didn't have to be as tall as my husband is, I mean taller than me, but dark hair and blue eyes. I mean, I dated people who did not fit that, but that was definitely my niche. yeah, definitely.

Carrie Bedient MD (02:10)

Okay, Abby?

Abby Eblen MD (02:12)

Yeah, everybody I dated before my husband was taller than my husband. The guys I dated before were six feet or over. He's like 5'11". And I always went for pretty eyes. That was my thing.

Susan Hudson MD (02:22)

Carrie?

Carrie Bedient MD (02:22)

So I tended to go for tall brown hair of any variety, usually light eyes and an engineer. And then I married my...shorter than I am, dark haired, dark eyed, doctor of a husband. And I have absolutely zero regrets. All I do get a fair amount of crap on a still semi-regular basis, considering that we've been together over 20 years now about how my type is engineers. And I am grateful every day that I didn't marry one, no disrespect to engineers, but I'm glad I found my doctor husband who knows what I'm talking about when I go off on a tangent.

Abby Eblen MD (03:00)

Yeah, you and the smart guy, how's that?

Carrie Bedient MD (03:02)

Yes, that was smart guy. I always hit that requirement.

Susan Hudson MD (03:05)

Yeah, with engineer versus physician as honestly my entire family that I'm married into and everything like that as engineers. They're brilliant people, but it's definitely a different personality. It worked out well for me just because I can get away from work, and the nice thing is I do have to say being in medicine, what we share, just like what we talk about on the podcast, I think most people are able to understand at least parts of it. Whereas when those engineers start talking things, I start doing Charlie Brown teacher, wah, wah, wah, wah, wah.

Carrie Bedient MD (03:41)

Yeah, I hear that. Okay, brilliant ex-boyfriends aside and current magical husbands, always relevant. Do we have any questions for today?

Susan Hudson MD (03:50)

We do have a question. Our question is, I'm a 35 year old female with no known fertility issues using frozen donor sperm. AMH 7.9, AFC 28, BMI 20 with healthy lifestyle. I've done three retrievals and have had dramatic drop offs after day three. What could be causing this and can anything be done to improve it?

I've tried split insemination between ICSI and conventional this last time and it made no difference. Clinic has said to choose a different donor. I've done similar protocols all three times. Could a protocol change help? Here's an example. Egg retrieval number two, 24 retrieved, 19 mature, 11 fertilized, 10 day three, three blasts, all PGT-A normal. Egg retrieval. 3, 24 retrieved, 18 mature, 15 fertilized, 17 day 3, 4 blasts, waiting on PGT-A.

Carrie Bedient MD (04:48)

Do any of you guys object to those numbers?

Susan Hudson MD (04:50)

No, I think that this is unfortunately part of the funnel effect of human reproduction. I don't think that there's actually anything wrong. You may not fit diagnostic criteria for PCOS, but your AMH and antral follicle count probably put you somewhere on the imaginary spectrum line.

Abby Eblen MD (04:52)

That's pretty good.

Susan Hudson MD (05:14)

I think you're probably normal. Everybody would love to have 10 tested embryos and we occasionally see that, but I don't consider that normal. Normally what I expect is from the day of fertilization to get about a third of those biopsied and you're not far off of that.

Abby Eblen MD (05:33)

Mm-hmm. Yep.

Susan Hudson MD (05:37)

I think you're normal.

Abby Eblen MD (05:38)

Yeah, and the body just doesn't make that many eggs well. If you make a whole bunch of eggs, in fact, sometimes the people that are the most disappointed are people who end up with a normal amount of blastocysts to test, but they start out with like 40. Well, your body doesn't make, and I would say somewhere over 20, you're starting to get in that range where you don't get as good of a conversion to blast. I think for somebody your age, I usually say two to four blast to test are pretty common and that's kind of what you got.

Carrie Bedient MD (06:08)

The other thing to think about is that sometimes the comparison that you're looking at is random internet whatever and they'll say, oh, you should be getting at least 75 % of your fertilized as blasts. And there's actually a decent chance that you are getting 75 % as blasts, but there's also a highly likely chance that a lot of those blasts aren't good because not everyone can earn an A in the class every single time.

Those are not the ones that are going to get biopsied and make it because they don't have the components they need to make it down the line. I would not lose a whole lot of sleep about this. The fact that you've got as many embryos as you do, four blasts, three blasts coming out of cycles like that, especially that are euploid, that's awesome. I hope the rest of your journey goes as smoothly and as beautifully as that does.

All right, let's talk about designer babies.

And this is different than designer clothes. But, I say designer babies tongue and cheek because all three of us know that that does not exist at all. But I would bet dollars to donuts that all three of us have had patients come in and say, so what is this about maybe getting a baby with, blue eyes at six four, that's really good at soccer with a dominant left foot and, and yep, more and more specific. So today what we're going to talk about is what genetic testing we can do, when we can do it, and what types of treatment we can do it for, and the overall look at how does genetic testing play into fertility treatment.

Susan Hudson MD (07:36)

I'm just excited to talk about this. This is honestly one of my favorite subjects because there's so much confusion out there.

Carrie Bedient MD (07:43)

Very much so. If you have a patient who comes to you and it's the first consult visit, so you really don't know anything about them yet, and you're starting to have the genetic conversation and they're saying, I want to have the healthiest kid possible.

And this can include patients who don't necessarily have standard fertility issues. Maybe they're planning for the future because they're gonna be in their 40s when they actually try and get pregnant, things like that. And they say, I wanna have the healthiest baby possible. What's the very first tool that all of us use for genetic screening when we're in that first consult?

Susan Hudson MD (08:18)

So we use a panel of tests called carrier screening. These tests, they started out years ago, maybe having 12 tests that we would look at, 12 genes. Now there's usually somewhere between four to 600 genes that we are looking at. And these are genes that are hiding in the family tree. you don't have...these diseases for the most part, there's some exceptions to the rule, but essentially these are recessive. You have to have one abnormal copy from the egg, one abnormal copy from the sperm for you to have a child that will show evidence of the disease or they're what we call X-link traits, which are carried on the X chromosome.

If you have a woman who has a copy of an X-linked trait, there's another X chromosome that has a normal copy so it doesn't show up. However, if you have an X-linked trait in a male offspring, that X-linked trait can be passed on to a son. They have an X and they have a Y. The Y doesn't compensate for the abnormal X and that son could have a genetic abnormality. Now, a lot of the tests that we look at when we're looking at these are kind of big bad and ugly. And what I mean by that is if you have two abnormal copies, these are sometimes things that are either life shortening or significantly life altering. Now there's a good handful of them that may be not a big deal. We all see those come across our table. The way I explain it is this helps you with planning. It doesn't mean you can or can't have a baby. It may change how you may want to conceive that child. Even if it didn't change that, if you knew, hey, if both me and my partner are carriers for a certain condition and I have a 25 % chance, that this child is going to have very special needs and requirements through some point in its life, that may make a difference on where do I deliver? Who's gonna be my pediatrician? Where do we want to get our general healthcare? What are support services that we may need to enlist going into our pregnancy? So these are not things that are meant to force you into a certain type of fertility care, but there is power in that information for you to make life choices.

Abby Eblen MD (10:59)

I just want to interject. For people who don't have a medical background, I usually ask people that and if they don't, I say, well, you probably at least had a biology class at some point. Just as a little primer, each of us has 46 chromosomes. If you're a female, you have two Xs. If you're a male, you have an X and a Y. One of the tests we're going to talk about in just a minute looks at counting those chromosomes to make sure that you don't have too few chromosomes or too many chromosomes.

The test that Susan has just been describing is a test to look at a gene. A gene is a little itty bitty tiny place on a chromosome. And as she said, it's only if you and your partner have an abnormality in pretty much the exact same gene that you would potentially have a 25 % chance of having an affected child. The only way we know to worry about that is if you have this expanded carrier screening test first to look and really see what you carry and what your partner carry.

And then if we figure out that you both carry the same thing, then that's a situation where you would be at risk, your child would be at risk, and you may want to consider doing IVF to prevent you from having that child. Or as Susan said, at least let your doctor know, your pediatrician know, so that the baby can be tested very early if you choose not to do that.

Carrie Bedient MD (12:10)

When you are talking with your patients in that intake visit and you're going through their family history, do you ever encounter sometimes people say, nobody's had problems having babies. And that's what they think we're asking for about their family history. What are we really asking about?

Susan Hudson MD (12:26)

We're also looking at other things that are just medical problems, whether they are a family that has random people who have extreme short stature, or they may have certain cancers that may tip us off, that there may be a genetic link to these cancers. Those are big things that usually we pay attention to.

Carrie Bedient MD (12:48)

When we're asking those in your family history, just so you know as you're preparing to go in into these appointments, one of the questions we're always gonna ask is who is affected, what are they affected with, and about how old were they when they got affected? Because there's a huge difference between somebody who is affected by something starting age 30 versus age 70. Breast cancer at age 70 is pretty common. Breast cancer at age 30 is a big old warning sign. Having some of that information and being able to put together Okay, it was my mom's sister who had this and it was my mom's cousin who also got diagnosed with that same type of cancer, for example. Having some of that information helps us to narrow it down because in addition to these panels for...recessive conditions where it takes one from each partner to combine, there's also cancer panels that are out there. Do you guys use them very often? Is it more just directed at someone who's got a bad history who comes in? How do you use those?

Abby Eblen MD (13:45)

We don't use those very often in our clinic, but we certainly refer them if they have a family history. And a lot of times in our community, the OB-GYNs are pretty good about looking at histories of breast cancer and ovarian cancer. And a lot of times they're already screened before they get to us.

Susan Hudson MD (13:57)

I'm pretty proactive about doing the cancer gene screening, especially when it comes to breast, ovarian, colon, prostate, pancreatic, gallbladder, those types of things. Those panels are pretty easily available. And I think that it's nice for people to have that piece of information. A lot of times, they're like, grandma had ovarian cancer. I didn't know that even had a had any implication to my health at all, or, I've had all these cancers in my family. I've always wanted some testing, but no one's ever offered. I am pretty proactive about that personally. What about you, Carrie?

Carrie Bedient MD (14:35)

Somewhere in the middle. Certainly if I hear anything in the history, I will offer that testing pretty quickly.

A lot of patients are pretty overwhelmed by everything. And so they hear genetic testing and they're kind of shell shocked along with all the other information we get them. So we get the carrier screening for autosomal recessive conditions, those are the big four, six, 800 gene panels. And they won't want to do the cancer screening. Some people will make the very deliberate choice. They don't want the cancer screening because having one of those genes doesn't guarantee that you will get XYZ cancer. It just means you're at higher risk of it and they don't want to know. They want routine screening and going on from there.

Abby Eblen MD (15:16)

A couple other caveats, sometimes I'll present this to patients and say, here's the option, here's what, oh, I've already done that test. I was at my internal medicine doctor or I was at my cardiologist or I was at my cancer doctor. I've already done that test. Well, just know that there's a lot of different types of genetic testing. The ones that we do, the tests that we do, looks at things that would affect a child typically in the first two years of life and would cause severe disease, disability or death.

If you think about things like the BRCA gene, even though certainly like Susan said, we can order that, that's not something that's typically on there or something that would affect you later, Huntington's chorea, that sort of thing. We don't typically do those types of tests. ⁓

Carrie Bedient MD (15:54)

And if you have had testing, oh, my doctor looked at the BRCA gene, for example, that test doesn't include the four, six, 800 genes that are recessive because it's geared towards generally breast cancer causing genes, not all of these silent potential threats.

Abby Eblen MD (16:13)

Sometimes people will say, oh, I had that done in my OBGYN's office. And still as soon as about two months ago, I had a patient, I said, well, let's just get it and see what was tested because some of these panels change over time. And like Susan said, some of the earlier panels didn't have many genes on them. Well, this panel was a panel that was just done a couple of years ago that only had 14 things on it. And 14 genes is much different than testing for 400 plus genes.

That's the other caveat. If we test for 400 and some odd things, there's a pretty good chance we're gonna find something that you carry. Whereas if only test the 14 most common, there's a good chance you won't test positive for anything, even if you carry some other unique trait or gene.

Carrie Bedient MD (16:53)

How do you answer someone who says, I'm really worried about having a child affected by autism? And it can be because there's nobody in their family that's affected and they're really worried, or it can be because there's a couple people with some sort of developmental abnormality, whether it's a formal diagnosis of autism or something else scattered throughout the family on both sides, or maybe each partner has one person that's affected. How do you answer those, we want to screen out for autism questions?

Susan Hudson MD (17:19)

Unfortunately, autism is one of those things that we know there are certain things that may increase your risk of having a child with autism, but there isn't a gene test to say your child is going to have this risk or not. The things that we know that can have risks that we see the most commonly are closely spaced pregnancies. So we do recommend if you have just had a child waiting at least one year until conceiving your second child. Some reason, very closely spaced pregnancies can increase risk of autism. And also the age of the male partner getting beyond about the age of 40, you start seeing increased risks of children with autism. These are risks. It doesn't mean it's an absolute. We know these are tendencies. But realistically, Are we gonna tell you not to use your partner's sperm because they're over 40? No, we have people, guys who come in over 40 to build their families every single day. We know it's an increased risk, just like we wouldn't tell a woman who's over 35, oh no, we can't use your eggs because it's an increased risk of Down syndrome. It's still a low risk, but it is statistically different than what it was 10 years ago.

Carrie Bedient MD (18:33)

These are all tests and questions and things we can do before somebody has really decided on any method of treatment. Some of these will really inform what kind of treatment we do. For example, if you find two autosomal recessive conditions, yes, there is a much higher likelihood that we're going to want to do IVF because of the advanced genetic testing, but it's not typically a mandated requirement. And those policies will differ from clinic to clinic. Now, what kind of genetic testing can you do for someone who is going through some of the lower tech fertility treatments? Ovulation induction using Clomid or letrozole, IUIs, ITIs, those types of things. What kind of genetic testing are those patients eligible to get?

Abby Eblen MD (19:16)

Those are tests that would be done after a patient gets pregnant. Through IVF we can take an egg and a sperm, put them together, test them genetically in the lab, but we can't do that if it all happens in your body. So those are the types of tests where you would get the NIPT test, it's tested late in the first trimester, and it really will give you genetic information, but that's after you're already pregnant. Many times when you see your OBGYN, that's one of the first things they'll talk to you about when you go for your first OB visit.

Susan Hudson MD (19:43)

The one thing that you can do and generally we only do this in the situation of recurrent pregnancy loss so two or more miscarriages or as I mentioned before somebody with extreme short stature not in line with the rest of their family is doing their chromosomes and if it's a recurrent pregnancy loss that's a test we would want to do on both partners. It's just a blood test. And as Abby mentioned, we all have 46 chromosomes, and we want to make sure that we each have 46 of them in that everything's in the right position, because sometimes those positional abnormalities can give us an idea of why miscarriages may be happening. Other tests you can also look this kind of goes along on the carrier screening, but there's a special tests looking at Fragile X, which can have some implications for people who have early premature ovarian insufficiency.

Carrie Bedient MD (20:41)

Definitely. If someone comes in and says, I've had this testing before. I had it when I was pregnant with my first child, and now they're struggling to have a second child. We always go back and want to cross-check. And like we've touched upon a little bit, genetic testing can mean a bunch of different things and patients don't always understand exactly what kind of genetic testing they had. So if you had genetic testing in your last pregnancy and we asked, can we see that? It's because we're trying to determine, did you have carrier screening? Which is something that typically those genes don't change, but the size of the panel might change. And that might be something that says, yes, we need to repeat this or, no, you've had it done, we're good.

The other type of genetic testing refers to this NIPT testing where...that's all well and good, but that applies to that pregnancy and is no bearing on your current pregnancy. If you've had chromosomes, the karyotype, that once it's done, it's done. You don't need to repeat that because it's not gonna change. Knowing some of the distinctions between the genetic testing you may have had previously and what we can do and what will change is helpful just so you know why we may say, no, no, you really do need this testing because what you had before was totally different.

So let's talk about IVF and why is genetic testing when a couple is doing in vitro fertilization different than when they're doing some other type of method of getting pregnant?

Susan Hudson MD (22:06)

But like Abby said, you're doing IVF or in vitro fertilization, we have egg and sperm outside of the body. So we can see the embryo before implantation. And essentially what happens is about a third of embryos that fertilize, sometimes more, Once they get to the day five, six or seven stage, we can tell what part of the embryo is going to become the placenta and what part of the embryo is going to become the baby. We can sample a few of the cells that are going to become a placenta and then do further tests called PGT or pre-implantation genetic testing that can help give us an idea of different risks or chances of getting pregnant or potentially having a healthy baby. We're going to get into all the details of the different types of PGT that are available, but that's the basic premise. The thing about when you're trying to get pregnant either the old fashioned way, just with intercourse or with IUI is that all those things are happening inside the body and there's no way for us to get a few of those cells to do this testing. In IVF, we know that when we're talking about just the basic chromosome number in half of the embryos that are created, even in a woman who is in their 20s or young 30s, half of those embryos are going to be chromosomally abnormal. And as we enter into the upper 30s and early 40s, those numbers of abnormal embryos are going to get quite high, even up to 90 plus percent when we're talking about somebody who's perhaps 43, 44, 45 years of age.

Abby Eblen MD (23:54)

And one other thing I'd interject too, just a way to keep all this straight, because it really, even I have to sort of think, okay, we're doing this testing on you, we're doing this testing on your embryo. So the Natara test or the expanded carrrier screening test we do on you, so that we can then see if we need to test the baby. If you have recurrent pregnancy loss, like Susan said, we do that on you to see if there's a structural abnormality in your chromosomes. But when it really comes down to checking the baby, those are the tests that Susan's talking about now. We check the embryo to see if the embryo carries something abnormal so that we can therefore choose which embryo to transfer. So it gets really confusing, but just think about this is the chromosome test, the big one, the expanded one is done on you. These tests are done on your embryos.

Carrie Bedient MD (24:38)

What's the most common version of PGT that we do? Because PGT is an alphabet soup. So let's start from the beginning. What's the most common type of PGT that we're doing that most people think about and know that we can do?

Abby Eblen MD (24:44)

So aneuploidy testing, and that's where we test to see if there's too few chromosomes, too many chromosomes. We can also see if there's a piece of a chromosome that's missing or a piece of a chromosome that's added. And sometimes we can even find if there is a structural abnormality in your own chromosomes by looking at the embryo. And the way we do that is if we see the same chromosome combination, like say chromosome one and chromosome 20, if we see some abnormality of that chromosome in all your abnormal embryos, that suggests that maybe structurally there's an abnormality in your chromosome that's actually being passed to your child or to your embryo.

Carrie Bedient MD (25:26)

And this testing, this PGT-A, again, not related to anything that you would have done before. And what is one of the major determinants of whether your embryos are going to be considered normal, which is euploid, or abnormal, which is aneuploid, on PGT-A?

Susan Hudson MD (25:42)

So the major determinant, as I mentioned, is the woman's age. Human reproduction is very inefficient. And as I mentioned, we would expect about half of your embryos to be chromosomally abnormal. If you're, I would say, under 35, between 35 to 40, probably gradually getting up towards maybe 60, 70-ish percent and then between 40 and up that number is going to be eking closer and closer to 100 percent. The closer you get to 45-46.

Carrie Bedient MD (26:18)

So what's the next PGT type in our alphabet soup?

Susan Hudson MD (26:22)

So our next PGT type is called PGT-SR. So PGT-SR is a very, very specific test that is done in people with recurrent pregnancy loss that in the source of the egg or the source of the sperm, we know because we did chromosomes on them for recurrent pregnancy loss.

That on one of their chromosomes, they have all the right amount of material, but some of that material is in the wrong place, whether it's on another chromosome or it's flip flopped into a different position. And this test can help us figure out which embryos are going to be compatible with life.

And not just have the right amount of material, but the right amount of material and positions that are going to still help us result in a baby.

Carrie Bedient MD (27:15)

Okay, so we've got our PGT-A, which looks at the number of chromosomes. We've got our PGT-SR, which looks at if we've got the correct number of chromosomes, but they're arranged in a funny way, what's another type of PGT?

Abby Eblen MD (27:26)

PGT-M, I can't say it, monosomy, looks for single gene abnormalities, the ones we've been talking about so much here. So if you and your partner did the expanded care screening test and say you both tested positive for spinal muscular atrophy or cystic fibrosis, then that's where this would come into play. First, we would check your embryos to make sure they had the right number of chromosomes. So if you think of that funnel, we'd get to the funnel and maybe have somewhere between two to four that have the right number of whole chromosomes. And the next level would be to test for the single gene abnormality. We would be able to determine if your embryo had two bad copies, which would mean it would be affected. One bad copy, which would mean it would be a carrier like you and your partner are. Or in some situations, you can have an embryo that's completely unaffected. In generally those situations, we try first to transfer unaffected embryos. And it also depends a little bit on the genetics of the condition.

Sometimes we don't want to transfer carriers because of a certain condition, but oftentimes we do transfer carriers and they turn out just as well as if somebody was unaffected or as an embryo was unaffected. But what we don't transfer embryos that have two bad copies because that embryo would be affected.

Carrie Bedient MD (28:37)

So why don't we just do the carrier screening on the embryo? Why don't we cut out the middleman, forget the parents, and just create the embryos and run the carrier screening on them?

Susan Hudson MD (28:48)

One technology is not at that phase yet. Number two, we only do this test when we know there's something to target. And by doing the carrier screening on the intended parents, we're able to be able to figure out what needs to be targeted. And then a specific probe, very, very specific to your particular abnormality is developed in the lab to make sure that we can detect your specific situation in your embryos. So it's very custom made.

Carrie Bedient MD (29:20)

Very much so. What about the last type of PGT varieties out there?

Susan Hudson MD (29:27)

So this is kind of jumping in the deep end of genetic testing and this is something called PGT-P or polygenetic. This is looking at either disease states that we can decide, hey, this embryo may have a higher or lower likelihood of exhibiting some sort of disease. Diseases in this category include heart disease, breast cancer, melanoma, schizophrenia, just to name a few. There's about 15 or so that are available. But it's not going to tell you if this embryo for sure is going to develop something because there's lots of things that play into it. Really, it is something used to help you rank. This embryo has less risk than that embryo does and then you making a decision on whether or not that is going to be a factor in how or what order you might transfer embryos in. Realizing your best looking embryo may not have the least risk of whatever medical condition you're concerned about.

Now there are some other companies coming out that are touting that they can go down kind of what I would say the deep end and looking at hair color, eye color, intelligence, aptitude in sports, artistry, name your thing. These are by no means mainstream and they are by excessive means, excessively expensive to perform. It's just recently that some of these have started to come out. It is a Pandora's box of, when are we making these decisions? And I think realistically for most people, in the way IVF works at this point, if we're lucky in a single egg retrieval, you're going to end up with one to three embryos or chromosomally normal. The likelihood of you having one of those three embryos being vastly superior in whatever you think the superiority is going to be is, it's pretty low. Unless you have unlimited financial means and you're just going to do cycle after cycle after cycle and have 10, 20 embryos that are chromosomally normal to compare to each other. I just don't think that there's a lot of need or desire. I know there's the exception to the rule and everything. And it also gets us into the situation of just because we can, is there a should?

Abby Eblen MD (32:03)

I was just going say earlier, it's like when you're looking for a diamond. If you're looking for a diamond, what do you value the most? The brilliance of the diamond, the clarity of the diamond, the size of the diamond? It's kind of like that with embryos. like Susan said, if we only have two or three to choose from, there's probably not going to be a huge difference. I think the only exception would be if, you had a high likelihood of schizophrenia, for example, in your family, and you said, I really don't want a child that has a high risk of this.

If you had three or four embryos, there may be one that's lower on that risk scale, but they may be higher on the risk scale for cardiovascular disease or for melanoma or something like that. So like buying a diamond, you can't ever buy the absolute perfect diamond because you can't get 100 % of everything in every diamond. You have to pick and choose what's more valuable for you. I think somewhere down the road, if we ever get to the point in the future where we can mass produce lots of embryos, which may or may not be the case in the future if embryo biopsies are done differently. But if you had a lot of embryos, if you had a hundred embryos, then this is where something like this may come into play because you would have more to look at. If you're just thinking, okay, I really want to pick for this, that, or the other thing, you would have more to choose from. But I think that's really far out there.

Carrie Bedient MD (33:13)

We've got our PGT-A, which is looking at the number of chromosomes, PGT-R, which is looking at the arrangement of them, PGT-M, which is looking for specific mutations, and PGT-P, which is kind of a catch-all looking at quote unquote best quality embryo and moving on from there. Anything that we have left out in the overall genetic testing discussion about what's available, what's out there for patients who need fertility treatment.

Susan Hudson MD (33:39)

I don't think we've necessarily left anything out. I would just like to reiterate that this testing is here to give you knowledge and that knowledge is to help you have power. And we want you to have as much information as possible. Some people want information, some people don't. There's not a right or wrong explanation. But especially when you're talking about going down the path of IVF and maybe not wanting to do say PGT-A, which is very, common. Most of our patients and all of our practices do PGT-A and not all of them, but most of them do realize that if you choose not to do that and you're not successful, that that actually can in some cases make it a little more challenging for us to figure out what's wrong in the future. If we're transferring embryos that are untested and you're not getting pregnant, we don't know, is it because of something else that's going on, which we can test, or are we transferring chromosomally abnormal embryos? Because we've all had that 30 year old who had 10 embryos biopsied and one was normal. Is that what we expect? No, that is not what we expect. But have we all seen it? And have we all seen it enough that we know that that can be a reality? Absolutely.

Abby Eblen MD (34:57)

Well, and the other thing too for younger patients, because traditionally when we first started doing this, we thought, it'll be great for older women. And we didn't do it. Many of us didn't do it in younger women under 35. But we know now that it's about a 50-50 proposition, even in somebody that's 35 or younger. If you do have a 35-year-old who has eight or 10 embryos, statistically about half of those are going to be abnormal. And still, if you have five normal embryos left, that's a lot.

But if you're the type of person that feels really uncomfortable having embryos left over, at least this is a way to kind of pare down the number that we think would really be viable possibilities for you.

Carrie Bedient MD (35:33)

Be prepared as you're going through this to potentially talk with a genetic counselor. They are excellent professionals that work hand in hand with your fertility specialist to understand what this information is, what it means, and what we can potentially do with it. We all work with professionals from a variety of different places that deal with genetics.

Sometimes patients will be, well, can't you just explain it to me? And the answer to that is maybe. There are things that I'm very good at explaining and I understand really well. There are other things that...Not only have I never seen in my career, but most docs will have not. And that's where having the specialist makes a difference. And genetics is its own medical specialty. We may be sending you to somebody else to get additional information because we want the best for you. And it's not because we suck at our jobs, it's because we're good at our jobs and we know what's out there and we want to make sure that you've got the absolute best.

All right, to our audience, thank you so much for listening. Subscribe to Apple Podcasts to have next Tuesday's episode pop up automatically for you. Be sure to subscribe to YouTube. That really helps us spread reliable information and help as many people as possible.

Abby Eblen MD (36:41)

Visit us on fertilitydocsunsensored.com to submit specific questions you have and sign up for our email list. Check out our new book on the IVF Blueprint at all major book sellers including Amazon, Barnes & Noble, and bookshop.org.

Susan Hudson MD (36:54)

Check out our Instagram and TikTok for quick hits of fertility tips between weekly episodes. And as always, this podcast is intended for entertainment and is not a substitute for medical advice from your own physician. Subscribe, sign up for emails, and we'll talk to you soon. Bye.

Carrie Bedient MD (37:09)

You

Abby Eblen MD (37:10)

Bye.