Can You Ovulate More Than Once Per Cycle? (Episode 546)

Full Transcript: Episode 546

Lisa Hendrickson-Jack:

Today, I’m sharing an episode about a very common question. Whenever I start working with a group of clients, this is typically a question that is asked when I go through the reproductive hormone cycle, as well as the follicular phase and how everything works, because it’s a very common misunderstanding that ovulation can happen more than once in a cycle. And there’s a lot of information out there that does allude to this myth, and yes, it is a myth. And in today’s episode, I go into some research and data to really bust the myth that, A, you can ovulate more than once, multiple times in the cycle. And also, there’s another myth that you can get pregnant when you’re already pregnant. So there’s this myth that human beings can have a situation that’s called superfetation. And that means that you’re pregnant and you literally ovulate again and get pregnant again for the second time. And you have two babies growing inside your body at different gestation rates. That is a myth that does not happen in humans. And so in today’s episode, I share a little bit about that to debunk it. And so if this is something that you’ve heard, then I think you’ll find this episode to be interesting. And of course you can always jump over to the show notes page and take a peek at some of the articles and research papers that I’m talking about in this episode if you want further information. So without further ado, let’s go ahead and jump into today’s episode to dispel the myths about double ovulations.

Okay, so let’s jump right into today’s episode. And so basically what we’ll be talking about today are two of the biggest myths about how the menstrual cycle works. And we’ve talked about a lot of the myths on the show, and I’ve done a few episodes recently where I’ve tackled some of the most common myths. And so some of the most common myths include, you know, the menstrual cycle is always 28 days, ovulation always happens on day 14, women are fertile every single day. And so those and other myths — what I’ll do is I’ll link some related episodes in the show notes page. So if this is an interesting topic to you and you really want to spend some time just debunking a lot of the common myths about the menstrual cycle and increasing your own awareness of how the menstrual cycle works, make sure to head over to the show notes page, which you’ll find over at fertilityfriday.com/269. And I will link all of the related myth-busting episodes.

In today’s episode, though, we’re going to be talking about the two big ones. The two main myths that I will be talking about in today’s episode are the myth of double ovulation — the myth that you can ovulate once in the cycle and go on to ovulate again. That is actually a myth. It is not true. It’s not possible. And we’ll talk about why. And then the second myth is that a woman can become pregnant, ovulate once in her cycle, become pregnant, and then while she’s pregnant she can actually ovulate again and become pregnant like twice. That is also a myth. It is not true. And we’ll talk about why neither of those two situations are possible. We’ll talk about what some of the situations are that can occur that can be misinterpreted for those two events. And of course, I’m drawing directly from the scientific literature, so I’ll be linking the studies to this episode for those of you who are very skeptical and want to see where this information is coming from.

So let’s start with the myth of multiple ovulations. I think the most important and potentially helpful aspect of this conversation is to start with just a basic foundation of how the menstrual cycle works so that you can start appreciating why multiple ovulations don’t happen in the cycle. For any of you who have charted your own cycles, it’s one thing to listen to someone like me talk about these events, but it’s another thing to actually chart your cycles. So if you’re listening to this episode and you find yourself thinking, absolutely not, this girl doesn’t know what she’s talking about, I totally disagree — then I would say the first step is to actually start charting your cycles for yourself. Because as soon as you chart your cycles, and let’s say you’ve charted your cycles for six months or twelve months or two years or five years or, like in my case, almost twenty years, then you really start to see and understand the biology of what happens in the menstrual cycle for yourself. Because it’s no longer in a textbook and it’s no longer a concept or an idea, but it’s actually your physical body, and you start to understand what changes happen throughout the cycle.

So let’s first start by taking you through the menstrual cycle. At the very beginning of the menstrual cycle, day one of your cycle is day one of your period — it’s day one of your true characteristic flow. And in order to have a true menstrual period, ovulation had to happen about 12 to 14 days prior. So it is possible to have bleeding if you didn’t ovulate. For example, if you’re taking the birth control pill, you can have bleeding whenever you stop — you take your sugar pills, or if you’re using the patch or the ring and you pull it out for a couple of days. But there was no ovulation prior to that bleeding. And so in the case of the birth control pill, that would be withdrawal bleeding. And if you are charting your cycles and you notice that you didn’t ovulate — you didn’t have a temperature shift, there was no ovulation, but you had a couple of days of bleeding — we can refer to that as anovulatory bleeding.

So I think the first thing to know about the menstrual cycle is that your true menstrual period happens about 12 to 14 days after ovulation in a healthy cycle. Okay, so you have your period, and then what happens is we get into the first half of the cycle. As you approach ovulation, your follicles start to develop in your ovaries, and as those follicles develop they produce estrogen. So as you approach ovulation, your follicles are developing, they’re producing increasing amounts of estrogen, and that estrogen has a number of different effects on the menstrual cycle — effects that you can actually observe. One of the effects that you don’t necessarily observe until you get your period later on is that estrogen stimulates the endometrial lining to grow. One of the effects that you can observe is that estrogen stimulates cervical mucus production. So for any of you who chart, you’ll know that as you approach ovulation you typically see a change in your cervical fluid — you might go from not seeing any to starting to see some lotion-y type or clear stretchy kind of like raw egg white type mucus, or you may just notice that when you’re going to the bathroom it feels really slippery when you’re wiping yourself. Either way, these are the effects of estrogen.

Now for those of you who are checking your cervical position, you’ll find that as estrogen levels rise, your cervix becomes softer, you may feel that it’s a little bit open, you may feel a bit of a dimple, and you may feel that it’s at a higher position in your vagina. Either way, there is a change from what happens outside of your fertile window to when you’re in your fertile window.

What is important to know about ovulation is that ovulation doesn’t happen at random. There are some animal species where ovulation may be triggered from sexual arousal, but with human beings it doesn’t work like that. We do not ovulate in response to sexual arousal and it does not happen at random. Ovulation happens because of a series of hormonal events. Estrogen rises to a certain point and once it rises high enough, it actually triggers our pituitary to release luteinizing hormone — and that luteinizing hormone, which is what the ovulation predictor kits test for, is what triggers ovulation. In a normal typical cycle, ovulation would happen anywhere from about 24 to 36 hours after that luteinizing hormone surge.

So you had the first half of your cycle, your ovaries were producing estrogen, it reached a certain threshold and then that triggered your luteinizing hormone, which then triggered ovulation about 24 to 36 hours later. When you ovulate, I just want you to picture what’s happening in your abdomen — your ovaries during ovulation actually burst open. The ovary itself actually ruptures and the egg comes out. The ovary physically changes during ovulation in order for the egg to come out. And once that happens, after the ovary ruptures, there is quite literally then a scar on your ovary because it just ruptured. The same follicle that was producing all the estrogen and that burst during ovulation then turns into the corpus luteum. The corpus luteum starts producing progesterone. You produce significant amounts of progesterone after ovulation, and you only produce significant amounts of progesterone after ovulation — there’s no significant progesterone production in the menstrual cycle unless you do ovulate.

Progesterone has a number of effects on the body that counteract the effects that estrogen was having before. Progesterone shuts down further ovulation. It actually closes the cervix and it stops the production of that cervical mucus that you were observing before. Progesterone stimulates the cervix to fill with a thick gelatinous mucus plug that is a physical barrier that prevents sperm from being able to swim through and access your cervix, your uterine cavity, and your fallopian tubes. And also, progesterone stimulates your cervix itself — for those of you who are checking your cervical position every day, after ovulation you’ll notice that the cervix does close, it feels more firm, and it goes into a different position in your vagina. So when you’re charting your cycles, you can feel the physical shift that happens in your body — the physical change in your cervix, the positioning and the feeling. You can feel it go from open to closed. This is a physical change that happens in your body and it’s biology.

So then the mucus — if you’re checking for mucus, what happens after ovulation in a typical cycle is that your mucus dries up either completely, or you’ll see a definite shift from what it looked like during your fertile window. These changes are all happening as a result of progesterone. And then what would happen in a typical cycle is that if there was no exposure to sperm, you’d get your period about 12 to 14 days later — or if you were trying to get pregnant or you had unprotected sex in the fertile window and there was sperm in your reproductive tract that fertilized an egg, then you would go on to become pregnant.

Now of course we know that a woman can release more than one egg at ovulation, because we all know that fraternal twins happen. But again, ovulation doesn’t just happen at random and it can’t just happen at any point during the cycle. What happens in a case where a woman releases more than one egg — it is possible, since the majority of us have two ovaries, for both ovaries to develop a follicle. As estrogen levels rise, it’s the same hormone cycle — you just picture both of the ovaries doing it at the same time. Once those estrogen levels reach the peak, the pituitary secretes luteinizing hormone and that triggers ovulation. So if there’s more than one follicle that is mature at the time of ovulation, then it’ll respond to that luteinizing hormone surge and eggs can be released from both ovaries, but it would happen on that one day — that 12 to 24-hour period. So ovulation can only happen on that one day, and then once you ovulate, we have a series of hormonal shifts and changes that actually prevent it from happening again.

Now let’s go ahead and talk about some of the events that are commonly misinterpreted as multiple ovulations. One of the great things about the internet is that you can Google anything you want and you’ll find evidence for and evidence to the contrary. And so even if you were to do a search for double ovulations, you’ll see all these articles that say women can ovulate twice, they can ovulate more than once. There’s one study that I’ll link in the show notes called A New Model for Ovarian Follicular Development During the Human Menstrual Cycle, and this study is cited in several different articles basically saying this is proof that ovulation can happen twice. Now what’s interesting about the study is that they’re looking specifically at follicular development — the study doesn’t actually confirm ovulation with some of the accepted ways that you can actually confirm ovulation.

So let’s talk first about how you would actually go about confirming ovulation in the menstrual cycle. In order to confirm that ovulation has actually occurred, there are a few different ways. One, if you’re charting your cycles, you confirm ovulation at home by monitoring your basal body temperature. Basal body temperature is a measure of your body’s resting metabolism. When you get up first thing in the morning before you’ve gotten out of bed, after you’ve had ideally at least five hours of uninterrupted sleep, you take your resting body temperature. What you’ll find consistently is that after you ovulate — after your ovary has released an egg — you start to produce significant amounts of progesterone, and that progesterone causes a change in your metabolism that you can actually measure on a chart. On your chart, you’ll see a group of temperatures pre-ovulatory that are within a certain range, and a separate group of temperatures after ovulation that are always higher. Those temperatures don’t drop back down — they just stay up because the progesterone actually increases your metabolism.

In addition to temperature, your cervical mucus will completely dry up or there’ll be a significant shift. Your cervical position changes as well — these physical changes that you can actually measure and write down. To fully confirm ovulation in the most scientific manner, you would either have to undergo daily ultrasounds, or you could have a blood test to verify your progesterone levels. Because you’re only producing significant amounts of progesterone post-ovulation, one of the ways that doctors will confirm if ovulation occurred is to actually test your blood. If your progesterone levels are at a certain level, the only explanation is that you ovulated.

Okay, so I wanted to preface it by that because I want to be clear that there are specific ways to confirm ovulation, and unless a person is actually confirming ovulation in a scientific manner, we can’t make the assumption that more than one ovulation occurred.

So let’s go back to some of the events that are often commonly misinterpreted as multiple ovulations.

The first is multiple waves of follicular development. As I mentioned, there is an article that is commonly referred to as evidence that women can ovulate more than once in the menstrual cycle. In this article they are measuring follicles via ultrasound throughout the cycle and drawing conclusions from that — but they’re not actually confirming ovulation in the accepted ways. They’re not testing for progesterone levels, they’re not doing daily ultrasounds to confirm the specific date of ovulation, and they’re not looking at basal body temperature or cervical mucus or any of the fertility awareness signs. What they’re doing is measuring the size of the follicles and drawing conclusions based on the changes in size. The conclusion of the study says: “The follicular wave phenomenon in women provides a new model for ovarian function during the menstrual cycle and will improve our understanding of the ovarian response to fertility and hormonal contraceptive regimens.” So they’re not verifying that ovulation happens more than once — they’re verifying that there are multiple waves of follicular development within the menstrual cycle. That is very different from confirming that ovulation happens more than once.

It is possible to move towards ovulation as your follicles develop and grow, they produce estrogen, you start to produce cervical mucus — and then something happens. If you are somewhere on the PCOS spectrum and your body is sensitive to sugars and glucose, or you are stressed, or you experience something significant, ovulation can be delayed. The first half of the menstrual cycle — the pre-ovulatory phase — is the most susceptible to disruption. If one cycle your cycle is 29 days and the following cycle it’s 45 days, that means that ovulation was delayed.

Multiple waves of follicular development can be misinterpreted as multiple ovulations, as well as multiple patches of cervical mucus, delayed ovulations, and double peaks. Let me paint you a picture. If your cycle happens to be really long, or looking back on a cycle, ovulation doesn’t occur until say day 30 or something like that, and you’re tracking your cycles — you may notice that you are having cervical mucus for several days and you think, okay, I’m going to ovulate now. But then your temperatures don’t rise and nothing really lines up, and then you might start to see cervical mucus again for a couple of days. That scenario is called a double peak. It’s very well-known, common, and documented within the fertility awareness world. It is not a sign that ovulation occurred twice — it’s a sign that your body was gearing up to ovulation, your hormone levels started to rise, and something basically suppressed ovulation and delayed it until a later time. If you were to have ultrasounds randomly scattered throughout that period of time, you would likely hear from the person interpreting your ultrasound that follicles are developing, and they may even say something that would make you think that ovulation is happening more than once. But again, in those situations, we have no confirmed ovulation — no sustained basal body temperature shift, no progesterone testing to verify that you are in the post-ovulatory range.

One of the last events that can be commonly misinterpreted as multiple ovulation would be positive ovulation predictor kit results. It is possible to have a positive OPK result and not ovulate. For some women — I’ll give the example of polycystic ovary syndrome — one of the signs of PCOS is elevated LH levels. Women with PCOS are known to have rapid LH pulse secretions, meaning some women with PCOS will secrete a lot of luteinizing hormone throughout their cycle. Some of these women will have positive ovulation predictor kits all the time, and it has nothing to do with whether or not they ovulated. Furthermore, ovulation predictor kits do not confirm that ovulation has occurred — they’re detecting for that luteinizing hormone surge, which in a typical cycle will occur about 24 to 36 hours prior to ovulation. A positive ovulation predictor kit multiple times in the menstrual cycle does not mean that you ovulated multiple times. It means that your LH levels were elevated multiple times. And those are two different things.

So to repeat that short list — events that are commonly misinterpreted as multiple ovulations include: multiple waves of follicular development as detected on ultrasounds; multiple patches of cervical mucus; delayed ovulation; double peaks; and positive ovulation predictor kits.

Okay, so we spoke about the reasons that ovulation can’t happen again in the menstrual cycle. Once you ovulate, you produce progesterone — it stimulates your cervix to fill with a thick mucus plug, it changes the cervix, it changes the position of the cervix, it dries up your mucus, and it suppresses further ovulation.

Now let’s talk about the second big myth — the myth of multiple pregnancies. The myth that it is possible to ovulate and become pregnant in a menstrual cycle, and then ovulate, whether it’s several weeks later or months later, and become pregnant again. This is a myth. The concept of getting pregnant while you’re already pregnant has a word — it’s called superfetation. And again, we have to take it back to how the menstrual cycle works.

I’m going to reference an article that talks about this in really great detail: The Concept of Superfetation: A Critical Review on a ‘Myth’ in Mammalian Reproduction. What’s interesting and helpful about this article is that it’s not just talking about human beings — it’s talking about mammals. So you can see and understand how and where some of these ideas come from, because there are certain species of animal where these types of things can occur. Once you understand how the human reproductive cycle operates, you can appreciate why this is something that just can’t happen.

So let’s talk about what would need to happen in order for a woman to get pregnant while she was already pregnant. Three main things would have to happen. The first thing that would have to happen is that she would actually have to ovulate while pregnant. The second thing that would have to happen is there would have to be sperm in her reproductive tract — in her fallopian tubes, her cervix, her uterus — sperm would actually have to be in there and alive in order to fertilize this egg. And the third thing that would have to happen is that the endometrium would have to be receptive to implantation.

Let’s talk about the first point — ovulation. After ovulation occurs in the menstrual cycle, you produce a significant amount of progesterone. The hormonal situation in a woman’s body before ovulation is completely different than the hormonal situation post-ovulation. Once she has ovulated, the corpus luteum causes a shift in hormone production — producing significant amounts of progesterone. During pregnancy, by the time a woman is 40 weeks pregnant, she is producing more than 11 times the progesterone that she was producing during the normal menstrual cycle. Pregnancy is a completely different hormonal time — it’s almost like a second puberty. You’re producing such high levels of estrogen and progesterone that it actually changes your body. First things first: ovulation is not possible in that hormonal state because the progesterone actually suppresses further ovulation.

In terms of the semen — in order for pregnancy to occur while pregnant, ovulation would have to happen, which is suppressed. Semen would actually have to be there to fertilize an egg. Now it’s well documented that when a woman ovulates, her cervix fills with a thick mucus plug, and sperm are not able to penetrate. There are a number of research papers where they test to see if the sperm is able to penetrate — and the sperm are not able to penetrate. Your cervix is closed. Once you’ve ovulated, the cervix actually closes and sperm can no longer gain access to your uterus. This makes sense — if our uterus was just open all the time to potential viruses and bacteria, that would really leave us more susceptible to infection. This is quite an important biological function of our bodies.

And what happens during pregnancy — as I mentioned, your progesterone levels increase significantly, and that actually causes the mucus plug to thicken. Erik Odeblad actually categorized the mucus plug that you have during pregnancy as a separate type of G mucus due to the increased level of progesterone. In other words, when you after ovulate, your cervix is closed and it fills with a plug that prevents sperm from penetrating — and once you get pregnant, that plug becomes even stronger. There will never be any sperm in your cervix or your uterus or your fallopian tubes because it is actually physically blocked by a mucus plug.

And the third thing that would have to happen is the endometrium would have to be able to accept a blastocyst. In order for pregnancy to happen, not only do you have to ovulate and there has to be sperm present and fertilization has to occur — but one aspect of pregnancy and how it works that many people may not realize is that there’s only a short window of time when your endometrium is actually receptive to a fertilized egg. Implantation — the process of actually having the egg implant into your uterine lining — there’s only about a four-day period, a four-day window, when implantation can actually happen.

It takes about five or six days — just shy of a week — for that fertilized egg to make its way into the uterus, and then there’s a short about four-day window of time when the uterus is receptive to a fertilized egg. Progesterone is crucial for priming the endometrium for implantation and for making the endometrial lining receptive to implantation. When a woman is already pregnant, her endometrial lining is not receptive to implantation — that window is done and closed. Her endometrial lining is in a completely different stage, and she has significant amounts of estrogen and progesterone flowing through her body that are causing the endometrium to develop in different ways to support the life of her growing baby.

So just to try to shatter this myth that a woman can become pregnant while she’s already pregnant — this is a biological function of the human body, not something that just happens at random. The main message is that pregnancy doesn’t occur at random — there is a specific period of time in the cycle when ovulation occurs, when a woman is fertile, there’s a specific fertile window, ovulation only happens on one day, it doesn’t happen multiple times, and implantation can’t just happen whenever either.

Similar to what we did with multiple ovulations, I wanted to go through a few situations that are often mistaken for superfetation. One is having multiple eggs fertilized from that one ovulation — if a woman develops more than one egg during that one day of ovulation, which is entirely possible, and potentially if she had sex with more than one person within her fertile window, then she could actually be pregnant with twins by two different fathers. That doesn’t mean that she ovulated more than once — but that could be misinterpreted as this concept of getting pregnant when she’s already pregnant.

One of the examples I’ve seen that would more commonly be mistaken as potential double ovulation and double pregnancy at different times is developmental retardation and embryonic death and reabsorption. Many of the situations I’ve come across where individuals are adamant that pregnancy happened more than once often involve a woman who is pregnant with twins, where one baby doesn’t develop normally. When they measure the babies via ultrasound, one baby will be a lot smaller than the other. And so it is possible to be pregnant with two babies and to have one baby not develop normally. There are documented situations of this when there may be exposure to infection or there’s some sort of morphological issue. In human babies, differences in the development of multiple pregnancies can occur, with most cases caused by pathological circumstances.

There are also situations where a woman may be pregnant with twins and one of the twins doesn’t survive. It’s really important to be critical when we hear situations like that. If a person is pregnant with twins and the twins measure differently, that is not confirmation that the woman ovulated while she was pregnant and conceived while she was pregnant.

Another example given in this article was conception during a pregnancy in retrogression — another possibility where a woman became pregnant and perhaps miscarried, but the fetus didn’t actually expel, and then she did have another cycle and then conceived. Again, these are not situations where a woman is ovulating twice while pregnant.

The reason that I feel it’s important to address and dispel these myths is that I just can’t imagine the stress that it would cause to think that you could be pregnant and still have to be vigilant and worry about not getting pregnant a subsequent time. My hope and aim is to educate and to share the information and to connect you with the science as much as I can.

Now with that said, I just wanted to conclude with two examples of how this could possibly happen and to illustrate what would have to occur in order for something like this to happen. In a human woman’s body, if there was some sort of developmental issue with the uterus — for example, women who have a bicornuate uterus, a type of anomaly where there’s a deep indentation in the uterus — and also in a case called uterus didelphys, another word for a double uterus — women who, for whatever reason when they were developing in utero, developed two uteri side by side. It is possible for women to have two uteruses, two cervices, and in very rare cases two vaginas. In a case like that it would be possible, because if you have two uteri then it’s possible for you to have two different cycles happening at slightly different times. But that’s a really rare condition that would at some point be identified. If you were having bleeding that was going on and you weren’t sure why, at some point you’d go to your doctor, have an ultrasound, and these issues would be identified. It would take something like that — a very, very rare developmental issue with the uterus — and a very incredible set of circumstances.

That brings us to basically the end of the episode. Essentially what we talked about today was the two major myths — the myth that ovulation can happen multiple times per cycle, and also the myth that you can be pregnant and then get pregnant again. What I aimed to do with this episode was to share the research and the science and the biology with you so that you can appreciate why these types of situations don’t happen. And I would encourage you, if you’ve never charted your cycles before, the best way to dispel these myths for yourself is to chart and to start to see the signs for yourself. The more cycles that you track, the more times that you see what happens in your body when you ovulate and the changes that occur — if you become pregnant at some point in your charting, you see how your cycles change and how your body changes when you become pregnant — you will understand for yourself how these reproductive functions work, because they will no longer be a mystery. You’ll start to recognize: this is actually biology. This is how my body works. This is why ovulation happens on only one day of the cycle. This is why the fertile window is quite short — shorter than we think — only five days long plus the day of ovulation. This is why when you’re pregnant, ovulation doesn’t happen again and you can’t get pregnant again while you’re pregnant.

The reason that this pertains to fertility awareness is that when I’m working with clients who are wanting to use this method for birth control, if you think you can get pregnant when you’re already pregnant, or if you think that you can ovulate and then ovulate again, that makes the method totally ineffective and it would be a complete waste of time to even learn it. This is one of the reasons why it’s so important to dispel these myths, especially in my line of work, and to help women feel confident about charting, and to help them know the science and biology of it — that’s through a combination of the research articles that we talk about on the podcast, but also by charting your cycles and seeing in real time what’s actually happening in your body.

I hope you found this episode helpful. If you were someone who believed some of these myths, I hope that it dispelled that. If you were someone who was feeling a little nervous about the concept of charting your cycle because of one of these myths, I hope that you feel a little bit more confident knowing that now. I hope you have a wonderful week. Until next time, be well and happy charting.