Birth Control Myths, Part 1: Risks for Infertility, Weight Gain, Cancer; and The Migrating IUD

Birth control. Contraceptives. Used by many but, dependent on the type, not always for the assumed or traditional purpose of pregnancy prevention. It actually has many uses, some more surprising than others.

It is also not just one thing – there are many different types of ‘birth control’. There are hormonal forms of birth control – the patch, the ring, or the pill. The shot. The implant. Some IUDs are hormonal, well others are copper. There are barrier methods such as the condom or the diaphragm. And then there’s what some people refer to as “natural” methods of birth control because they don’t involve hormones or a device (though I never like the term natural because I find it stigmatizing)- withdrawal (or the “pull-out” method) and fertility awareness methods (also known as FAM). Finally, there is emergency contraception.

I ran a thread of polls on Twitter that determined that more than 50% of people (52.8% to be exact, sample size: 248) felt that they knew a lot about birth control and 82.6% of people felt they understood how birth control worked. Interestingly though, 40.7% (243 sample size) voted that they did not remember being taught about birth control in school, despite there being health and sexual education classes which are presumably supposed to spend some time educating students about this very important subject. I unfortunately lack demographic data as it was a Twitter thread (I do know that 72.4% of my voters were 21-30 years in age), but this is still very interesting. It suggests that many people either were taught at home or by friends/family (making the accuracy/trustworthiness of the information they know questionable), in a medical setting (likely accurate, but less extensive due to appointment time lengths and so on), or they did their own research (which you know, I support, but that presents the problem of the internet and what lies beneath!). Something for any providers, educators, or teachers reading this to think about as we search for ways to provide people with reliable information and teaching on important subjects such as this.

*Disclaimer: This blog is intended for informational purposes only. The information on this blog should not be used as a substitute to medical advice or medical treatment. As always, your Primary Care Provider, a doctor, or another health professional is your best resource for specific questions and medical advice. If you believe you or a loved one are experiencing a medical emergency, please contact 911.*

Myth: You should wait a few months after stopping birth control to try and conceive.

53.7% of 231 voters said false. This is correct.

The fear here is often miscarriage, which is a common concern to have. It is a concern you have even when you haven’t been using a hormonal birth control method within 3 months of a pregnancy. I think, frankly, every pregnant woman worries about miscarriage at some point in their pregnancy or even low key throughout, especially if you’ve experienced a loss before.

I am here to tell you that you don’t need to add to your worry if you’ve been using a hormonal birth control within 3 months of trying to conceive (TTC) – the idea that this can cause a miscarriage is a myth.

When you stop the pill it may take some time for your cycle to regulate again though – so this can cause a delay in TTC. Generally, your cycle should resume within a few months, but if it’s taking longer or you have a history of irregular cycles, PCOS, or other conditions that may affect your menstruation – contact your HCP. If you’re TTC at all – contact your HCP! It can be helpful to have a preconception appointment to discuss all the important things that come with conception and pregnancy, and look at any risk factors you might have.

I think that people sometimes associate long term use of birth control with infertility. A systematic review from 2018 (spanning 32 years of literature) showed that length of use/type of birth control had no negative impact on fertility. I have not come upon any research that shows a negative impact (as always, I invite you to share any reputable resources with me if you have them because I would love to include them!) – and many articles and experts contest this as birth control actually has many positive effects such as balancing hormones and easing the symptoms of endometriosis.

Age is one thing that does impact fertility, and this is well known and acknowledged. I think people forget this though, and it’s easier to think that being on birth control for 10 years is associated with infertility (especially with all the misinformation online) as opposed to thinking: hey, I’m a bit older than I was 10 years ago maybe that has something to do with it (or it could be one of a myriad of other risk factors, or it could be your partner). But, just because you are older doesn’t mean you can’t get still conceive – it just means it might take longer, or you may need to work with a fertility specialist.

Myth: Using (hormonal) birth control will make me gain weight.

*hormonal is in brackets because I did not include this word in the polls.

70.1% of 231 voters said this is true. Frankly, it depends on the type and is kind of complicated.

A Cochrane review from 2008 (updated 2011) found no association between weight gain and combination contraceptives (meaning they contain both progestin and estrogen ), however data was limited and more studies are needed (also, 2008 was awhile ago and the data would be even older). Most studies that are done on this type of birth control (the pill, the patch) found that there are a variety of weight changes reported – loss, gain, or no change at all, and it’s pretty divided and none of the evidence is strong enough to associate their use with any particular weight change.

The ring may be associated with some small amount of weight gain (<1 kg generally), according to several studies. The NuvaRing website also lists this as a possible side effect, however you have to keep in mind they have to include this if anyone had this as a side effect.

The most common culprit for weight gain is the birth control shot. The one designed to last 3 months (Depo-Provera) can cause more water retention. Pills with increased estrogen levels are also common culprits, as they cause increased appetite. The implant has also been commonly discontinued as a result of weight gain.

Least common culprits are hormonal IUDs and progestin-only pills, as well as the combination pill and patch which I mentioned earlier.

Keep in mind that weight gain may occur simultaneously with hormonal birth control use, but it may not be to blame. Always check with your HCP if you have a significant gain or are concerned about weight gain while on the pill as there could be something else going on.

In short – some types of birth control may cause weight gain in some people, while it may not in others. If it does cause it, it can be quite complex, but it may be due to water retention or increased appetite. It may also be related to your weight prior to starting the birth control and demographic differences. Avoiding the shot, implant (though most studies are based on the Norplant and Jadelle implants only) or high estrogen pills may help, especially if you are someone who gains weight easily.

Myth: Taking or using any form of birth control increases my risk for different cancers.

*Note: this is in reference to hormonal birth controls – however again, I failed to include that wording in my original question.

51.8% of 224 voters said this was true. For some types of cancer it has been shown to, but for other types ORAL contraceptives (and IUDs) actually decreases the risk (based primarily on observational studies – this just means that it was observed, not studied in a lab, so you cannot prove that oral contraceptives caused the cancer since it did not occur in a controlled environment).

So what types have an increased risk with oral contraceptives?

Breast and cervical cancer.

The studies that have been done have somewhat mixed results. A study from 2017 showed a 20% increase in relative risk of breast cancer. So, this study compared the occurrence of breast cancer in women who were using or recently discontinued use of an oral contraceptive, and those who had never used oral contraceptives. The risk seemed to be type dependent, and increased based on duration of use. Stopping the pill did show a decrease in risk. Older studies have shown the risk to be lower or decreased after stopping the contraceptive, yet still commonly type dependent (related to triphasic pills like Tricyclen, they have 3 different doses of estrogen and progestin).

Results are similar for cervical cancer, in that duration of use seems to increase risk (5+ years) when you compare oral contraceptive users to those who have never used them. Several studies have shown there to be a decline in risk when women discontinue use though.

Notably, there may also be a slight increase in risk of liver cancer as well, with use over 5 years. Many long term medications can impact the liver so this is not surprising.

What type of cancers is it protective against?

Endometrial, ovarian and colorectal cancers all show a decreased risk with oral contraceptive use. Longer duration of use decreases risk even more for endometrial and ovarian cancers.

If you want to read more about how oral contraceptives increase or decrease your risk of these cancers, check out the National Cancer Institute.

If there is a risk of cancer, why would I take the pill?

Because there are also protective factors and many benefits. It may help with the symptoms of a chronic condition; the pain or heaviness of menstruation; acne; pregnancy prevention; and other issues. You know what I always say… discuss your concerns with your HCP. There are always non-hormonal options to look at if you feel concerned.

What about the other types of hormonal birth control?

There is minimal research on their relationship with cancer, just because they aren’t as old as oral contraceptives. Studies like this have to be done over a long period of time or with a forward-looking perspective. However, there does appear to be an increase in risk of breast cancer with any hormonal contraceptive.

There is some evidence that IUDs decrease the risk for ovarian cancer by up to 32%.

Myth: If I use birth control, I may have trouble having children in the future.

64.2% of 226 voters believed this was false. That’s correct – but there’s something important to note.

I touched on this in the first response and I’ll just refer back to this systematic review from 2018, which showed no negative impact on fertility from hormonal birth control use.

It actually may have a protective effect related to fertility since it helps to balance your hormones, and is often used by those with endometriosis or PCOS to ease symptoms.

However, hormonal birth control may give people a false understanding of their cycle and its regularity. That’s why methods like FAM can actually be useful to practice prior to using contraceptives – so that you know your cycle.

This is also why doctors sometimes recommend you getting off the pill a bit before TTC – so that your cycle can regulate and you get a better idea of what it’s like. That way if you discover it’s irregular, and you’re having trouble getting pregnant, other causes can be examined. I imagine the myth that you “need to be off hormonal birth control for at least 3 months” was born from a misunderstanding of this request.

Myth: IUDs commonly tear through the lining of the uterus.

74.7% of 221 voters said this was false. YEP – it can happen, but it is not common.

I just want to note if you google this, the first site that comes up is an attorney’s site for a law suit against Mirena. So that is certainly problematic for those of us fighting the good fight.

Can this happen? Can my IUD tear through my uterus? Yes, it can happen, with ~1/1,000 IUD insertions (and this is based on older data). But it is uncommon – also it’s very rare to see it perforate other organs in the abdomen.

It’s still a risk you should be aware of and that should be discussed with you by a healthcare provider. They are doing this so you know what to look for because it can happen, not to scare you. That being said, perforation can be silent so there may be no symptoms. One woman did not have her perforation diagnosed for 43 years after the insertion!

It can happen with any device and is associated with some risk factors such as insertion by a physician who has little experience with the procedure (many of the other factors are rare or debated in the literature). Abdominal pain is a common symptom, if you are symptomatic.

An ultrasound is performed and laparoscopy is usually effective to remove the device.

Take-away message: it is uncommon, but still something you should be aware of. It’s like when you see a drug commercial on TV that lists every possible side effect including death. Be aware, but if you look into it, the chance is usually not high they just need to include it because it has happened to someone at some point.

It’s also important to attend your follow-up appointment after insertion so that the position of the device can be checked.

***Part 2 of this blog is here


2 responses to “Birth Control Myths, Part 1: Risks for Infertility, Weight Gain, Cancer; and The Migrating IUD”

  1. […] You can find the first part of this series here. […]


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