How Hormonal Contraceptives Affect Time to Pregnancy (Episode 512)

Full Transcript: Episode 512

Lisa Hendrickson-Jack:

This is the Fertility Friday Podcast, episode number 512.

Today I’m excited to share the third part in the three-part series we have been going through, basically addressing that question of how does the pill impact fertility. In our first episode in the series, we looked at how the pill impacts the menstrual cycle specifically — how long does it take the menstrual cycle to normalize post-pill? In our second episode, we took a deep dive into how the pill affects ovarian function and how long it takes your ovaries to normalize post-pill. And in today’s episode, we’re asking a different question. We’re looking at how does the pill impact fertility — specifically, does the use of contraceptives potentially delay time to pregnancy? And as we did in the previous two episodes, today we are taking a look at what the research has to say.

And so in today’s research study that we’re looking at, this is something I alluded to in either one or both of the previous episodes. But when you’re looking at research on the pill and how it impacts fertility, the most common type of study that you find is a study that provides you with the kind of summary results of the total overall impact of fertility on an annual basis. So typically, the more recent studies that I’ve looked at will simply give you what the overall percentage of conception was in a year, and that’s how they look at it. And so they’re very easily able to say, you know, the pill is a reversible contraceptive method and X percentage of women successfully conceived within a year, and then — finished, done. And it looks great on paper. But it’s harder to find a more nuanced study that actually takes the fertility statistics and lists them on a month-to-month basis, so that we get a sense of: okay, well, you’re saying X number of women conceived within a year of coming off of contraceptives, but how many of those conceived in month one and month two and month three? And it may not seem like a big deal, I think, in the research world, because I think when we’re looking at data like that from the research standpoint, it makes sense to categorize it like that. But because I’m in the weeds with my clients on a daily basis, it’s a really significant difference for somebody to be conceiving in the first two months coming off of contraceptives versus the 11th or 12th month, especially when the expectation was that we would come off contraceptives and conceive immediately after a lifetime of being told that we could conceive on every single day. So in today’s study, we’re looking at a research paper that breaks it down month to month. And like I said, this is not an easy thing to find.

I actually want to start by reading something from the study, which I find interesting. And so in the introduction of the study, the researchers are actually kind of giving their general sentiment. They’re talking about how even though the majority of couples do desire children at some point, it’s really common for them to delay this until they’ve established themselves in their relationship and career, etc., which I think is something we can all relate to. And this is interesting: to embark on many years of contraception not knowing what effect this can have on the ability to conceive can cause concern. Young women may approach contraception with an ambivalent attitude because of this underlying desire to guarantee and prove their fertility. So I think it’s interesting that they use the word ambivalent, because this really resonates. Because we’re not provided with complete information on anything related to our fertility, and because the attitude toward contraceptive use is so cavalier, we’re not really looking at this critically and we’re not really provided with the tools even to do so.

The study is called “Is Previous Use of Hormonal Contraception Associated with a Detrimental Effect on Subsequent Fecundity?” — the study titles are definitely, they leave something to be desired. But in the study, they surveyed almost 3,000 women and they looked at how their choice of contraception impacted their time to pregnancy. So from when they stopped using contraceptives and started trying for pregnancy, how long it took them to conceive. And what’s interesting about this study is that they compared a variety of contraceptive methods. They compared the non-hormonal method condoms. They looked at the most common birth control pill, so the combined oral contraceptive — and again, combined just means that they’re using the combination of synthetic estrogens and progestins. They looked at the progestin-only pill, they looked at the IUD, the hormonal IUD, they looked at the shot, and they looked at the implant. And so they’re actually breaking down how long it took for these women to conceive after coming off.

And so these types of studies are really helpful and important. And this is why I wanted to break this series into three parts — so that we could really look at this question of how does the pill impact fertility? Because what I was stressing in the first two parts of the series is that we can look at the impact on ovaries, we can look at the impact on the menstrual cycle, but it doesn’t necessarily mean that someone’s going to come off the pill and not conceive. So we also have to look at how the pill impacts time to pregnancy specifically. But I think it’s important to look at all three of those pieces and think about what we can learn from it.

So in this case, when they looked at women who were using condoms — so they were not using hormonal methods, their cycles were not affected by any type of artificial hormone — on average it took about four months for these women to conceive naturally. And that’s in line with just the general information. You know, your average healthy couple has about a 25% chance of conception per cycle. And so that’s right in line with the average that we are aware of.

And so when women were coming off of the oral contraceptive, so the combined oral contraceptive pill, it actually took twice as long compared to the women who were using condoms. So compared to the condom users, when women came off of the contraceptive pill, it took them twice as long. It took about eight months instead of four months. And some of the other data I’ll list and share with you here: the progestin-only pill took about six months, so it took about 50% longer — so instead of the four months, it took six months on average to conceive. The IUD was eight months, so it was in line with the results for the combined oral contraceptive.

And whenever I talk about the pill and its impact on fertility, I think one of the questions I get the most is: well, what about the IUD, and what about this and that? And I think that it’s important to remember that when we’re looking at hormonal methods, they’re not all the same, but they have similarities. And I think with the IUD, there’s a specific question around that because of the way that it’s marketed and promoted and the way that medical professionals talk about it. So with the IUD in particular, women are told all of these interesting things. They’re told that it’s low dose. They’re told that it is localized. So they’re told that when you insert a hormonal IUD into the uterus, the hormones stay in the uterus and they just hang out there. And that’s interesting, because when I put lotion on my skin, if that lotion has parabens or chemicals, those chemicals go all throughout my bloodstream because I have a circulatory system, yet somehow you expect me to believe that if I put a hormone-releasing device inside my uterus, the hormones are just going to stay right in there. So that’s a huge myth that is absolutely essential to bust. And so it’s important to note that the hormonal IUDs — so like the Skyla and the Mirena and other brands — those are hormonal methods. And so they have hormonal effects similar to other hormonal methods like the pill. And there’s absolutely no — I don’t even understand how it’s possible that medical health professionals with degrees are telling women that the hormones just stay in the uterus. It makes literally no sense and it’s completely incorrect. Obviously, all you have to do is look at the side effect profile and speak to anywhere from five to ten women who’ve ever used the IUD to know that the hormonal impact and side effects are very similar to that of the pill.

So that was a bit of an aside, but I think it’s worth saying. So in this particular study, back to the study, the women who came off of the hormonal IUD, it took a similar amount of time to conception compared to the oral contraceptive pill. And if we want to look at the specific numbers, the average for the contraceptive pill was 7.7 months, and the average for the IUD was 8.4 months. So it was actually slightly longer statistically.

So the shot fared the worst of all of the options, and I think that is really important to note. The shot took anywhere from 15 to 18 months. Women who had discontinued using the shot took the longest to conceive. And in this particular study, the implant was somewhere in between — on average, it was taking about 10 months.

So this is important information, this is really useful for us to know. Because essentially it’s showing us that hormonal contraceptives are a reversible method of birth control and our fertility does return. But what they’re not telling us is that there’s this temporary period of subfertility. And so within those averages, obviously some women conceived sooner and others conceived later. But the whole point of the series is to empower us with this information so that we can make choices.

Another important and interesting piece of this study is that they divided the users into what they term short-term versus long-term use. And in this particular study, they defined long-term use as two or more years. And when they divided the groups into short-term and long-term, that’s when we started to see more of a variation in terms of how long it took women to return to fertility. So the information I shared with you — the statistics — those were the averages. So if we looked at the contraceptive pill, women who had used it short-term, so two years or less, the result was similar to the women who had stopped using the condom. So if you used the pill for a year or six months, in this particular study, the average time to pregnancy was about four to five months compared to the average of eight months.

And another thing to point out: the injection had the longest time to pregnancy. So even with short-term use, the shot on average took about nine months. So women who stopped using the shot, even after what they termed short-term use — which was under two years — on average it still took nine months to conception. And then for long-term use, it was 19 months. So women who used the shot for more than two years were in the 19-month territory in terms of the average time it took to conceive. And again, this information is not something that’s always broken down, not always shared, and potentially many health practitioners aren’t necessarily made aware of it, because a lot of these studies are simply looking at the one-year total.

Interestingly, of all the hormonal methods, the method that had the least negative impact on the return of fertility was the progestin-only pill. So in this study, short-term use — when women used for two years or less — the time to pregnancy on average was four months, in line with condom use. And for long-term use, it was five months. So interestingly, in this particular study, the progestin-only pill had the most favorable result. Unfortunately, progestin-only pills don’t have the same degree of efficacy as the combined hormonal contraceptive pills, but it is something to be aware of.

And so the way that the researchers concluded the study, they said: based on the above results, it appears that the contraceptive methods that act primarily by ovarian suppression — such as the combined pill and the shot — might have a transient residual negative effect on subsequent fertility, particularly in the women who already have potentially compromised ovarian function. They go on to say that overall, contraceptive users should be reassured that the effect on their later fertility is small.

I think it’s important to stress that again: there’s no research to indicate that any of these results are permanent. It’s not that we’re sitting here in a state of terror about the impact of the pill on our fertility. I think that the reason I like to highlight this specific piece of the conversation so frequently and so strongly is that I know the psychology of women coming off birth control to conceive. This question of when to have a baby is a very complicated one, and for many of us it takes years and years of planning and preparation. And in this current day and age, we really are waiting for a lot of things to align in order for us to feel comfortable enough to start our families. And we’re also told nothing about our fertility, so we’re kind of taking it for granted that when we’re ready, we’re just going to be able to have a baby.

And the bigger thing that’s pushed in our early 20s and late teens is birth control, because we’re told that we can get pregnant all the time. So we’re always on defense — always preventing, preventing, preventing — because of course we’re assuming it’s just going to happen. And so when we are entering into conception with that mindset, and there’s no balance, it’s not like we’ve also been told about how to be offensive about this. Like, when you’re on offense, you’re planning ahead. But you’re not thinking about: well, how do I prevent but also preserve my fertility and put myself in an optimal position so that when I’m ready, I can just go ahead and make that switch?

And that’s from my perspective where fertility awareness really comes in. Because for women for whom that is an option, it really provides this third option. It provides this option where we can still actively avoid pregnancy — we can learn a specific fertility awareness-based method, we can understand the rules, we can know that the sympto-thermal method has been shown to be upwards of 99.4% effective when used correctly — so that can really give us that confidence we need to be able to trust in this non-hormonal kind of non-conventional birth control method. And what’s interesting about it is you can prevent pregnancy while simultaneously optimizing your fertility, so you can do both at the same time. You’re handling the defense part of it by being really intentional about how you use the method, understanding how to manage your fertility, understanding what to do in that fertile window. But you’re also able to optimize your fertility, to monitor your menstrual cycle health, your hormonal health, to see where you’re at. If you’re coming off the pill, you can kind of see where you started from, and as the cycles go by and you’re doing a variety of things to support your hormonal health and replenish nutrient stores — restore some of those nutrient deficiencies that were caused by the pill, for example — you can actually see that progress.

So if we go back to the study, it’s telling us that there is this temporary period of subfertility that we should be aware of. But then what do we do to manage that? And so of course my suggestion is that we take this into consideration when we’re considering when to come off birth control, instead of just doing what we’re apparently told by our healthcare professionals — which is to simply stay on them until the minute before we’re trying to conceive and just assume everything’s going to be fine. If we look at what the actual research says, it would indicate that it would be in our best interest to give ourselves a little bit of a buffer period.

I’ll just take a moment to read something from Real Food for Fertility in the pill chapter. In a separate study, not only did it take about twice as long for past oral contraceptive users to conceive compared to non-users, oral contraceptive users had a significantly lower chance of conceiving within the first six months after coming off the pill. This trend of reduced fertility continued for a full year after the participants had stopped taking oral contraceptives. And according to the researchers: we believe that women who plan to become pregnant should be aware of the possible, even though temporary, delay in their ability to conceive after the cessation of pill use. Furthermore, it has been accepted generally that couples could be considered for an infertility evaluation if they had tried unsuccessfully to conceive for at least 12 months after stopping all birth control methods. In view of the findings of this study, at least 15 months before an infertility evaluation might be an acceptable interval for prior pill users.

So this is interesting in terms of what the researchers are suggesting. They’re saying this is showing us that there’s a temporary period of subfertility after coming off contraceptives, and they’re also saying that if that’s true, then maybe we should be adjusting the recommendation for when we give someone an infertility evaluation. They’re implying that if somebody is evaluated for infertility within this transition phase, they could be incorrectly identified as infertile, when if they took a little bit longer before they went that route, they might actually be okay. And so that’s huge. By no means am I suggesting that we delay medical care if we need it. I do think it’s important to seek support for fertility issues sooner than later, particularly on the male side — at least for testing to see where we’re at. But I do think it’s important to consider that when we’re in this period of subfertility, it could be that you appear to have a problem when really your body’s still in that transition and things could look differently several months later.

One last point I want to make before we wrap up: when we’re looking at time-to-pregnancy studies, it’s useful to consider that when they’re selecting candidates, they are typically screening out candidates that had pre-existing conditions or pre-existing menstrual cycle issues prior to partaking in the study. So anybody that had irregular or problematic cycles that were put on the pill for those reasons — often these participants are excluded from the study. And that can be challenging, because many women do have cycle issues and many women are put on contraceptives for managing those. So if you’re one of those people, and the studies themselves exclude those people, then how do we know how it could affect you? And so I would argue that if you’re put on the pill for specific menstrual cycle issues, then the pill doesn’t actually solve or cure or fix those issues. It simply masks them and suppresses those symptoms so that you are now asymptomatic. If you had 50- or 70-day cycles and then you’re on the pill and you get a bleed every 28 days, well, that symptom is now gone — but the actual issue that was causing your cycle to be like that was not solved. And so arguably, when you come off the pill, that issue is still going to be there. So if that’s you and you’re planning to come off the pill to conceive, it’s even more important that you come off sooner, because you’ll still have to address whatever it was that was causing your cycles to be irregular.

So I hope that you enjoyed this three-part series. I certainly enjoyed putting it together. If you can think of someone who would benefit from hearing it, the link to share today’s episode is fertilityfriday.com/512. And the three episodes in the series were 510, 511, and 512. If you are wanting to dig into the research, you can head over to the show notes page at fertilityfriday.com/512. For more FAM Research Series episodes, head over to fertilityfriday.com/research. And of course, to dive in more to this question of how to optimize fertility, make sure to grab your copy of Real Food for Fertility on Amazon — you can find additional details over at realfoodforfertility.com. So with that, I hope you have a wonderful week — whenever you’re tuning into the show — and of course, as always, until next time, be well and happy charting.