Nature vs. IVF: Why Getting Pregnant Before Doesn’t Mean IVF Will Be Easy

Many patients assume that if they have gotten pregnant naturally before, IVF should be simple. But IVF and natural conception are not the same process.

In this episode of Taco Bout Fertility Tuesday, Dr. Mark Amols explains why IVF is incredibly powerful, but still cannot perfectly duplicate every hidden filter, timing system, and biological checkpoint that happens inside the body. From sperm selection and fertilization to fallopian tube transport, embryo transfer timing, uterine receptivity, egg recruitment, and embryo grading, IVF can reveal parts of reproduction that nature usually keeps hidden.

This episode explores why someone may have children naturally but still struggle with fertilization, embryo development, or implantation during IVF. It also explains why a failed IVF cycle does not mean failure — it may provide valuable clues that help guide the next step.

IVF is not worse than nature. Nature is not better than IVF. They are different routes toward the same goal. And sometimes in fertility, the route matters.

Thanks for tuning in to another episode of 'Taco Bout Fertility Tuesday' with Dr. Mark Amols. If you found this episode insightful, please share it with friends and family who might benefit from our discussion. Remember, your feedback is invaluable to us – leave us a review on Apple Podcasts, Spotify, or your preferred listening platform.

Stay connected with us for updates and fertility tips – follow us on Facebook. For more resources and information, visit our website at www.NewDirectionFertility.com.

Have a question or a topic you'd like us to cover? We'd love to hear from you! Reach out to us at TBFT@NewDirectionFertility.com.

Join us next Tuesday for more discussions on fertility, where we blend medical expertise with a touch of humor to make complex topics accessible and engaging. Until then, keep the conversation going and remember: understanding your fertility is a journey we're on together.

Transcript

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Today we talk about the fertility fight of the nature versus IVF. I'm, Dr. Mark Amols, and this is Taco about Fertility Tuesday. So who wins in the fight between nature and ivf? Well, spoiler alert. IVF may have better technology, but nature has had a few million years of practice. And that's what today's episode is really about. IVF is incredibly powerful. It can bypass blocked tubes. It can help with low sperm counts. It allows even embryo testing. But IVF is not a perfect replica of natural reproduction. Sometimes IVF does things better than nature, and sometimes nature does things better than ivf. And sometimes IVF reveals problems that nature was quietly filtering the whole time. So today we're getting into the fertility fight of the century. Nature versus ivf. No gloves, no referees, just sperm, egg, embryos, and biology being biology. Now, this episode may surprise a few people, because sometimes the body can do things naturally that IVF struggles to do. And that kind of sounds backwards, because when people think of ivf, they think, well, this is the most advanced technology. This is science. This is in a lab. Shouldn't IVF be better than nature? And the answer is, yeah, sometimes. When it comes to overcoming blocked tubes, well, IVF wins. When it comes to low sperm counts, again, IVF wins. When it comes to picking the best embryo to put back, IVF wins again. But IVF is not this perfect copy of natural reproduction. It is more like we're trying to recreate the most important parts of nature with medications and procedures and lab techniques, protocols. But nature has a lot of filters that we don't really recognize and unfortunately, are not good at duplicating. And that's because nature is just not. Sperm and egg meet up. It is sperm selection, egg selection, tool transport, embryo development, uterine timing, implantation signaling, immune regulation, and probably a bunch of other biological details we don't fully understand. Basically, nature is running a very complicated fertility obstacle course. And when it comes to ivf, it's our best attempt to recreate that course. But sometimes we're just not as good. One of the common questions I get asked is, hey, I got pregnant before. Why is IVF not working now? Isn't it better? I'll even have patients who have had multiple kids, and then all of a sudden, they do ivf, and. And they're not successful, and they're thinking, how is this possible? That's a really fair question to ask. And that's because from the patient perspective, it should kind of be easier. I mean, if sperm and egg can find each Other going through the body, why can't it, find it in a simple dish? If embryo was implanted perfectly before, why, would it struggle now? But even when the body has proved it could get pregnant, sometimes ivf, isn't easy. And the answer is that IVF and nature are not the same process. They may be trying to reach the same goal, but because they take different routes, routes matter, and that can affect things. Let's start with sperm, for example. In natural conception, sperm don't just get an Uber ride to the egg. They have to pass through the vagina, the cervix, the cervical mucus, the uterus, the, the urotubal junctions, go through the fallopian tubes. They have to get past the cells surrounding the eggs, the zona pellucida. And then finally, they get to interact with the egg itself. Like I said, that's not an Uber ride. That is a selection process. The reproductive tract is filtering sperm the entire way. And it's not just movement. It has to respond to chemical signals. It has to survive these environments, has to undergo a thing called capacitation, which is, what allows it to go into the egg and then it has to activate the egg. So when someone gets pregnant naturally, it may be because nature did a really good job selecting the perfect sperm. Think of it like the best club to go to for dancing, except nature has a bouncer, and that bouncer is really strict. And it's not letting every sperm into the club. When you have relations that there are millions of sperm that are ejaculated, but only about 50 sperm make it to the egg, that is an extremely strict selection process. If you use that scale on a real club, no one would get in. But when we do IVF, we put 50,000 sperm onto every egg. That is 1,000 times more sperm. And the reason is because we're not as good at selecting the sperm. I've had people who have had multiple kids and come to us for gender selection, and then we go and do ivf. Sperm looks amazing, by the way. Then we do standard insemination, and nothing fertilizes. Can you imagine how shocking that is? I mean, in their mind, they're like, we do this all the time, and Dr. Amo's clinic sucks. Why can't they get the sperm to fertilize? And the thing is, there's nothing wrong with the sperm. The sperm looks good. The problem is the process of selecting it is different in nature. It took those millions down to 50 sperm. So the small imperfections we cannot see in the testing are selected out. And so only the best sperm make it to the egg. But we're not that good. Again, we need to put 50,000 sperm over each egg. And so now those imperfections are not removed. And now a person who can get pregnant without any problems will struggle with fertilization. Ivf, it's because we can't filter it as well as nature. Nature wins in this fight. Even when using things like the Zymot chip or other technology, it doesn't always guarantee fertilization. Yes, ICSI may guarantee the sperm gets into the egg, but it's not just a simple sperm eats egg, boom. Embryo fertilization is not a handshake. It's more like a rocket where every switch has to be flipped in the right order for it to work. So just because you put a sperm in the egg doesn't mean it activated the egg. And then we have to remember too, there's another side to this. There's even the egg. Maybe it would have done fine with one sperm, but this sperm, it's not going to work as well with, because there's more imperfections in that sperm that the ache just can't overcome. Now, this doesn't mean ICSI is bad. ICSI is not just good. It allows people to have success where they normally couldn't. I myself could never have kids without icsi. One of the greatest things about IVF is it's very revealing. With natural conception, we have no idea what happened. Maybe the eggs weren't released, or maybe they never fertilized, or maybe the embryos stopped growing. But in ivf, we can look at these things. But that can also be brutal because now, you know, the number of follicles, the number of eggs, how many were mature and how many fertilized. So we don't see the imperfections in biology because it doesn't have a spreadsheet. Another thing we underestimate is the fallopian tube. It's not just plumbing. It's not like egg goes in, sperm goes in and whoops, embryo comes out. The fallopian tube is very active. It's a living environment. It actually helps the sperm survive, helps with fertilization, it supports the early embryo, it controls the movement of the embryo and provides it with nutrients and signaling, and it helps the embryo fall into the uterus at the right time. But in ivf, we bypass the fallopian tube. That doesn't seem like a big deal. Matter of fact, sometimes the fallopian tubes are blocked and it's a Good idea. But when we bypass it, are we creating other issues? Well, I can tell you, most of the time, no, it doesn't create a lot of issues. But there is a small percentage of time that when we're bypassing the fallopian tube, we may be introducing timing issues. See, normally the embryo goes down the fallopian tubes and falls in the uterus. And some people might have longer fallopian tubes and slightly shorter. And normally it falls in around day five, maybe sometimes day six or day seven, depending on the embryo and the person. So we try to match nature by putting on day five of progesterone. But humans are not machines. They don't do the same thing every time. And because that travel through the fallopian tube is not going to be identical in every person, we're making an educated guess on, when that should be. And it's a pretty good estimate. Medically, it actually works most of the time. But as you can imagine, sometimes we're putting an embryo too soon, maybe sometimes too late, and sometimes it's just not synchronized. And this is one of the hardest things about ivf. You can have a good embryo, you can have a good look at lining. You can even have a very smooth transfer and not get pregnant. Because implantation is not just about placement. It's about timing. It's about signaling. It's about synchronization. It's about the embryo and the uterus having connection exactly at the right moment. And that just seems crazy. How can we not be better than nature? But it's because we don't know everything. We don't know that timing, and we have to make an estimate. So here's a situation where IVF looks like it should be better and could potentially create problems. Let's also talk about the uterus. When we are getting the uterus prepared for a transfer, we're not doing things naturally. And so we're adding potential other issues. For example, I've seen people, when we go to get their lining ready, we create things like small vacuoles in their uterus, yet when they do it naturally, those don't show up. And it's important to remember that it's not like the uterus is made of Velcro and the embryo just needs to stick. There's more to it than just sticking. There's an active biological process going on. And so the question is, when we do ivf, are we kind of messing with this biological activity and potentially causing problems? Again, I'm not saying IVF is bad. I'm just saying, when it doesn't work, don't always look to yourself that there's something wrong. Keep in mind, just because you got pregnant in the past doesn't mean that with IVF it's going to be just as good. Because your body may not do as well with IVF because of all these issues that IVF could be causing. Even embryo grading. Keep in mind that, yes, when we look at embryo grading, we do notice that there is a higher implantation rate when we do grading. But it's not like we actually know what's going on in nature. There is different judging of the embryo. See, we're just looking at morphology, but, in nature, it's able to look at other things we can't see. And so when we're putting these embryos back and we're thinking, why didn't work, nature may have already knew it wasn't going to work. Here's another interesting thing when it comes to ovarian stimulation and egg selection in life, here's another example. Look at egg recruitment. In nature, we usually just make one follicle. Life takes all those follicles and picks the very best one to release. But in ivf, we give you medication to make multiple eggs release. Some of those eggs were never meant to be released. Now, this is one of the biggest strengths of ivf, but sometimes we have to at least consider that some of those eggs that would have never been released may not be the natural winner in life. And potentially we are getting eggs that would have never worked in nature. Those 15 eggs that you were able to retrieve, only one of them would have been released. And maybe that one is the best one. Sure, the other ones may work, but it's important to understand this is not biology. It's not natural. And so there is going to be some failure in this because we are doing things outside of danger. And although it may seem like it should be better, it's not always better. And are you really surprised? I mean, think about it. In ivf, it's all about snapshots. We check the estrogen, we check the progesterone. We're looking at lining thickness, embryo development. We're even checking follicular sizes. But in the end, those are data points we're not watching all the time. But in nature, it's a live operating system. It's constantly ingesting hormones, not just at night or once a day. It's constantly checking the tubal movement, the uterine contractions. All those things are being monitored, which we don't get when we do ivf. So it's not surprising that we're not going to be as good as nature. Now, it's important to understand IVF is not worse than nature. I want to be very clear about that. What I'm saying is that nature is not perfect, because if nature was perfect, well, there wouldn't be a need for fertility clinics. That's where IVF comes in. We can bypass the blocked tubes. We can help with severe male factor fertility, like myself. We can allow information to be seen in the growth of the embryos to find out where other problems may be. We can even test the embryos to find out if someone has multiple abnormal embryos and causing multiple miscarriages. Whereas with nature, we just have to say, oh, well, so this isn't nature good, IVF bad. The real message is IVF is different. It solves many problems, but it cannot perfectly copy every biological filter, signal, or timing. So who won the fight? Well, technically, it wasn't a fight. And what you should take away is that just because you had a child naturally doesn't mean IVF is going to be simple. You may not do as well as you think. You only need one egg to get pregnant every month, but that doesn't mean you're going to make 15 eggs with IVF, because your ovarian reserve may be low. And yet you still got pregnant. But now, in the IVF world, you won't do as well, because it's a little bit more complicated than that when it comes to ivf. The second thing to come away with is that, IVF can reveal problems we could never see during natural conception. But just because we see their fertilization issues, we have to remember that some of those things we may have created just by doing ivf. And then probably the last and most important thing, a failed IVF cycle is not a dead end. One of the greatest things about IVF is we're able to make adjustments. So maybe now we need to do DNA fragmentation testing. Maybe we have to change the timing, use icsi, or even adjust by doing the natural transfer cycle. The point is, don't blame yourself. Because although IVF is a treatment, it's also diagnostic. It's able to show us the part of reproduction that's normally hidden in natural conception. In the end, nature is powerful, but it's not perfect. An IVF is powerful, but it's not magic. And sometimes the hardest part of fertility treatment is accepting that we don't have control. We can control a lot, but not everything. So when someone says, but I got pregnant before, the answer is not, well, that doesn't matter. It does matter. It tells us pregnancy was possible, but it does not guarantee IVF will be simple. Because IVF and natural conception are not the same process. They might be the same goal, but they're not the same process. Maybe you've been in a situation where you've wondered, why didn't that work when other things have. Maybe you have a friend who's going through this and they're struggling with this concept as well. Or, maybe you know, someone who's going to go through ivf, who's had kids, who's going to maybe for gender selection. This is going to be a great podcast for them. Help set those expectations and help that question of why. As always, I greatly appreciate everyone that listens to this podcast. If you love this podcast, please tell your friends about us. Give us a five star review on your favorite medium. But most of all, keep coming back. I look forward to talking to you again next week on Taco Belt Fertility Tuesday.