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    The Effects of Birth Control: An Interview with Professor Johannes Bitzer, Part 1

    Updated 21 September 2021 |
    Published 11 October 2018
    Fact Checked
    Dr. Johannes Bitzer, PhD
    Medically reviewed by Dr. Johannes Bitzer, PhD, Professor emeritus of obstetrics and gynecology, University Hospital of Basel, Switzerland
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    Want to find out more about the effects of birth control on the female body? Read the first part of our exclusive interview with Professor Johannes Bitzer, former president of the European Society of Contraception and one of the leading experts in the field of birth control.

    This is the first part of our two-part interview with Professor Johannes Bitzer. The second part of the interview can be found here.

    Which contraception methods have the least side effects?

    “If you look at just possible health risks and side effects, we could say that one of the least ‘risky’ methods is probably the copper IUD,” Professor Bitzer says. 

    It doesn’t have a negative impact on metabolism or the cardiovascular system. If you place it properly, there are no major gynecological complications. Taking the very broad view, the copper IUD has a very good risk-to-benefit profile.

    “The most complicated issue is actually with hormonal contraception,” adds Johannes Bitzer, who further explains that there are two basic types of hormonal birth control pills. One is combined hormonal contraceptives, which contain progestogen and estrogen. The other group only contains progestogen. 

    All the combined oral contraceptives (COCs) have a cardiovascular risk, especially of venous thrombosis. The risk is low, but it can be a dangerous complication. Fortunately, it’s very rare, but the risk is there, and it increases when you take COCs.

    If you take hormonal contraceptives without estrogen, you don’t have this thromboembolic risk. So progestogen-only contraception also has a favorable benefit/risk profile. Moreover, progestogens can be taken as pills, implants, and intrauterine systems.

    Professor Bitzer explains that with birth control, it’s more of a tolerability issue. The side effects you might have aren’t dangerous, but can be rather uncomfortable, especially those regarding bleeding irregularities. And here the combined oral contraceptives have additional benefits: they regulate the cycle, are good for your skin, and protect against certain health conditions.

    All in all, COCs present the most complicated picture: They have benefits, but there are also risks. On the general level, the copper IUD is probably the birth control with the least risk, followed by progestogen-only contraceptives.

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    Which birth control methods are the most effective?

    “Many studies have shown that the most effective methods are these long-acting methods we’ve been talking about, namely IUDs and hormonal implants. They are almost 100 percent effective. Nothing is exactly 100 percent, but they are close — around 99.5 percent,” says Professor Bitzer. 

    He also adds that other methods like the pill would also be similarly effective, but not with what we call typical use: “You need to take the pill every day, and people have difficulty sticking to the schedule.”

    So if you want maximum effectiveness with minimum hassle, long-lasting birth control methods are best.

    What happens if you miss a week of birth control pills?

    When you forget your pill matters. Johannes Bitzer says of all the times to miss a pill, forgetting to take it after the seven-day break creates the greatest risk of pregnancy. Most people still take the classic pill with 21 days of active pills, followed by a seven-day break or seven days of placebo pills. Forgetting the pill within the first week after the break creates such a high risk of pregnancy because follicles in the ovaries started growing during the break. When they’re not suppressed by regular intake in that first week, breakthrough ovulation occurs.

    “So when you forget one or even two pills during the first week, you need to take emergency contraception because you’re not protected very well anymore,” says Professor Bitzer. “If you forget one or even two pills in the middle of your package, just take the pills you forgot later. This is not so risky, because you have seven days of regular intake, which is good for the suppression of the ovaries. These are the general rules. When you are not secure, you need to use emergency contraception in addition to your pill.” And using condoms is also an option.

    Can birth control make breasts bigger?

    Regarding breasts getting bigger because of birth control, Professor Bitzer says that what sometimes happens, especially when people first start taking birth control, is the estrogen component in the pill causes some water retention. “This is not really breast growth, it is more of water retention inside the glands, the tissue.”

    Can birth control pills cause breast rashes?

    According to Professor Bitzer, rashes are rare. They don’t usually have anything to do with the pill. Often, they’re just coincidental. There are rare occasions when the body reacts to the progestogen in the pill, especially after exposure to sunlight. This could cause skin coloration. It is rare, but that is a consequence of the pill.

    Can birth control pills treat Polycystic Ovary Syndrome?

    According to Professor Bitzer, “Yes, they can help treat the symptoms of PCOS. They cannot heal PCOS, but we can quite effectively treat the symptoms.”

    He also says that the most important symptoms to treat are cycle irregularity, heavier bleeding, acne, and hirsutism. They can be very effectively treated with birth control pills, especially pills that contain anti-androgenic progestins. These progestins counteract the effect of testosterone to effectively treat the symptoms.

    Read this next: a detailed interview about PCOS with Professor Tahir Mahmood

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    Does taking the pill for a long time affect the cycle?

    Professor Bitzer says that this has been studied very extensively out of concern for people who start taking the pill when they’re very young and continue taking it for 20 years. Researchers wanted to know if they develop problems with their cycle or fertility. In fact, some people don’t get periods after they stop taking the pill. This is called amenorrhea. However, studies have shown that people who experience this actually had this problem before they started taking the pill, but they didn’t realize it because taking the pill gave them regular bleeding. “The pill itself doesn’t cause endocrine problems, but the endocrine problems may appear after stopping the pill,” explains Professor Bitzer. 

    Classic endocrine problems are PCOS or hypothalamic amenorrhea — for people who take hormonal birth control, they’re often not detected until they stop taking it.

    Can you lose fertility after taking the pill for years?

    According to Professor Bitzer, “It has become very clear that pill use protects fertility. You get less infection, fewer ectopic pregnancies, of course. Regarding fertility, you’re better off using the pill than not.”

    How long should you wait to get pregnant after reversible contraception?

    Professor Bitzer says you don’t need to wait: There isn’t a negative long-term effect. You just get off the contraceptives and get pregnant.

    Can birth control pills cause strokes or aneurysms?

    According to Professor Bitzer, we should be careful when talking about the cause of these serious conditions, because they’re usually caused by a combination of factors. The birth control pill is a risk factor.

    Says Bitzer, “There is some association between the pills and stroke — a very low risk, but there is some association. There is n