There are many reasons you might take the birth control pill, from regulating your menstrual cycle to suppressing hormone disorders like endometriosis or PCOS to, of course, preventing pregnancy. You can take the pill for years—even decades—before trying to conceive, which leaves us wondering: does birth control affect fertility later in life? There’s a ton of info out there, and all kinds of stories of so-and-so getting pregnant (or not) after taking the birth control pill. But what does the research say?
In this post, learn more about:
What are the different types of oral contraceptive pills?
Before we dive into whether the birth control pill affects fertility, it’s helpful to understand the different types of pills. There are many different brands and each come with their own potential effects. That’s because each one can contain different amounts of hormones, and even different forms of synthetic hormones.
Generally, there are two types of birth control pills, based on the hormones they include:
combination pills (A.K.A. combined oral contraceptives or COCs) which include both estrogen and progestin
Combination pills are the most prescribed and used, but there are a few reasons why you would be prescribed a progestin-only pill instead:
if you have an estrogen-dominant disorder (like endometriosis)
if the side effects of a combination pill are too intense
if you have a history of blood clots, breast cancer or high blood pressure
If you get migraines with aura
If you are currently nursing
If taken correctly, all birth control pills are equally effective at preventing pregnancy, and your doctor can help you find the right one to match your goals (which could be improving acne or decreasing your period flow, alongside preventing pregnancy) and minimize side effects.
Does the birth control pill contribute to infertility?
The hormones in the birth control pill prevent ovulation by stopping follicle development and limiting follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The pill is short-acting, which is why you have to take it every day for it to work properly. That means that once you stop taking the pill, its hormones should clear from your system in a few days and ovulation should restart—and you can try to get pregnant. If you had regular cycles before starting the pill, you can expect them to get back in their usual groove once you stop hormonal birth control. But, if you didn’t have regular cycles pre-pill, they’ll likely be irregular once again after you stop taking it.
If you’re trying to conceive post-pill, you can use at-home LH tests to help confirm that ovulation has started again. If you’re having trouble picking up that LH surge (even after following our handy ovulation test guide), then it’s time to talk to a doc about getting a more complete workup.
Infertility happens for many different reasons, some of which we know and can treat, and others that are less conclusive. But, the pill doesn’t negatively affect fertility from a hormonal perspective.
Does the birth control pill affect your ovarian reserve?
In a study that included over 27,000 American women aged 20 to 46 years, those who were on the combination pill on average had 23.7 percent lower levels of anti-Mullerian hormone (AMH), compared to those who were not on a hormonal contraceptive. (Reminder: AMH is a marker of ovarian reserve, which helps estimate how many eggs are left.) Those who used a progestin-only pill, had AMH levels that were 14.8 percent lower than non-users, and for the hormonal IUD, average AMH levels were only about 6.7 percent lower.
What’s important to note is that, though AMH levels were on average lower than those who were not taking the pill, this is to be expected. If you were to measure your ovarian reserve while on the pill, it makes sense that it’s lower than off it, because the hormones in the pill decrease stimulation to the ovary so that you never actually progress to ovulation in your cycle, effectively skipping it. But this shouldn’t be confused with the pill depleting your ovarian reserve; it’s a temporary suppressed state, that returns to normal once you stop taking the pill.
Does birth control prolong fertility?
On the flipside, you might be wondering if taking the birth control pill can save up your eggs or delay menopause, and ultimately extend your fertility. But just like how the birth control pill doesn’t contribute to infertility, it doesn’t increase fertility either.
The pill works by stopping a mature egg from developing (thus, no ovulation), but it doesn’t stop the runner-up follicles (the sacs that hold eggs) from their usual routine of developing then breaking down. Dive into the details about birth control and egg quantity here.
Does having an IUD affect fertility?
Like the pill, IUDs are considered to be a safe and effective birth-control option with no known long-term impacts on your fertility. Whether you use a hormonal (progesterone-based) or non-hormonal (copper-based) IUD, once removed, your body should go back to its baseline quickly—as early as one month post removal but up to a year in some cases. On rare occasions, the insertion of an IUD can lead to an infection or damage the uterine cavity (causing scar tissue) which could affect fertility. There is also some research into whether long-term hormonal IUDs might have a negative impact on the uterine lining by contributing to changes in gene expression. Physical changes in the endometrium have been observed to revert back to normal within one to three months post IUD removal, whereas changes in endometrial gene expression can persist for up to a year. That said, studies have reported average conception rates of 70% to 85% within a year of IUD discontinuation, which is similar to those who were previous oral birth control users.
Does the pill cause cancer?
You may have heard that the pill can both cause and prevent cancer—so which is it?
The pill and breast cancer
There is a relationship between hormonal birth control and breast cancer. In a nationwide study of all reproductively-aged women in Denmark, use of hormonal contraceptives increased the relative risk of breast cancer by 9% with less than one year of use, and 38% with more than 10 years of use, compared to those who had never used it. That’s one extra case of breast cancer for every 7,690 women using this form of contraception for one year.
The pill and ovarian, endometrial and colorectal cancer
There is evidence that the pill protects against ovarian and endometrial cancer. In a similar demographic in Denmark, the use of the combination pill prevented 21% of ovarian cancers during use. This effect disappears when the combination pill is stopped and wasn’t shown in those using progestin-only pills.
What happens if you become pregnant while on the pill?
Like all birth control, the pill is not 100% effective (though it does come close). If you notice pregnancy symptoms while on the pill, stop taking it and talk to your doctor immediately. There is some evidence that becoming pregnant while using an IUD can slightly increase the risk of an ectopic pregnancy compared to non-users.
The bottom line when it comes to the pill?
Like all medication, there are pros and cons to using the birth control pill. But these largely have to do with side effects as you’re using it or your unique medical conditions that could impact its efficacy or increase the risk of certain side effects like blood clots. Fertility specialists don’t view hormonal contraceptives as a risk to future fertility (other than the fact that by using birth control you’re delaying when you start trying to conceive and age is a factor when considering egg quality and quantity).
If you’ve been on the pill a long time and want to learn more about your reproductive health, it may be worth stopping before you’re actively trying to conceive (you should also start a prenatal asap—more on that here). If the pill was masking any symptoms that could affect your fertility, they’ll be worth investigation with your doctor.
Pros and cons of the birth control pill
Prevents pregnancy when used properly (99% effective)
Helps regulate cycles
Can help endometriosis and PCOS symptoms
Improves hormonal-based acne
Can reduce the risk of ovarian cysts forming
Potentially protects against ovarian, endometrial and colorectal cancer
Can have side effects for some
Can cover up ovulatory issues, especially when started at a young age, which can delay diagnosis and treatment