Birth control is confusing, whether you are curious about the options, considering a change, or think your chosen method may have let you down. Can you get pregnant with an IUD, IUS, contraceptive implant, or vaginal ring in? Or if you’re on the pill?

Can I get pregnant with an IUD (intrauterine device, “the coil”) in?

No form of contraception is 100% effective, so it is possible to get pregnant with an IUD. However, it is highly unlikely. An IUD is a small, T-shaped plastic device that’s inserted in your uterus by a specially trained doctor or nurse. When inserted correctly, an IUD is over 99% effective. An IUD works by stopping the sperm and egg from surviving in the womb or fallopian tubes. They may also prevent a fertilised egg from implanting in the womb. The IUS contains copper, which is toxic to sperm.

Once the coil is in place, you shouldn’t have to think about it each day or each time you have sex, making it a great choice for women in stable, long-term relationships. It won’t protect you from sexually transmitted infections, which have the potential to harm you, your fertility, your partner, and any future pregnancy.

It is also possible to fall pregnant with an expired IUD. Depending on the type, they last between five and ten years. You can get pregnant as soon as an IUD is removed.

If you do fall pregnant with an IUD, it is crucial to inform your doctor as soon as possible, as conception in spite of the presence of this device is associated with a number of adverse outcomes for mum and baby, including miscarriage and preterm delivery.

Can I get pregnant with an IUS (Intrauterine System, “the hormonal coil")?

It is possible to get pregnant with an IUS but very unlikely. Insertion happens in a similar way to the IUD process described above. It also comes with the same STI risk. Many women call their IUS by the brand name Mirena, but there are a number of other brands, including Levosert, Kyleena, Jaydess, and Benilexa. An IUS works differently from an IUD. It works for 3 to 8 years, unless removed. An IUS prevents pregnancy by releasing progestogen which prevents you from releasing an egg each month. It does not contain copper. Less than 1% of women a year will get pregnant with an IUS, but if you are using one suspect you are pregnant, it is vital to seek medical attention as soon as possible. Conceiving with an IUS in puts you at increased risk of ectopic pregnancy, among other problems.

You can get pregnant immediately after an IUS is removed. It’s local to the uterus, so it does not affect your hormone production.

Can I get pregnant while I have a vaginal ring?

It is possible to get pregnant with a vaginal ring but unlikely. This form of contraception is over 99% effective if used correctly, according to the NHS. It is also known by the brand name NuvaRing. Even with what they call “typical” use, it is 91% effective. You have to take the ring out and insert a new one each month. You can usually get pregnant right after you stop using it.

Can I get pregnant with a contraceptive implant, such as Nexplanon?

Yes, but, again, it’s rare. As we’ve covered, no form of contraception is 100% effective. If implanted correctly, a contraceptive implant is more than 99% effective.

A contraceptive implant is a 4 cm plastic bar that steadily releases a synthetic hormone (progestogen) that prevents pregnancy. A specially trained doctor inserts it under the skin on the inside of your arm. It keeps you from ovulating and also thickens your cervical mucus, making it difficult for sperm to get through and fertilise an egg. This is extremely effective.

Fewer than one woman in 1,000 who has the implant as contraception for three years will get pregnant. It's very useful for women who know they don't want to get pregnant for a while but, like an IUD, will not protect you or your partner from STIs. Your fertility will return very soon after you have it removed.

Can I get pregnant while I’m on the pill?

You may know someone who has gotten pregnant while on the contraceptive pill. This has less to do with it being an ineffective method of contraception than with a woman taking it incorrectly. If you take it incorrectly or have severe vomiting and diarrhoea, there is a chance you could become pregnant.

If taken correctly (at the same time and every day for the 21 days prescribed, then taking a 7-day break, etc., or as indicated if you are on a tailored regimen), the contraceptive pill is over 99% effective. There are a variety of brands, but they all work to prevent pregnancy by thickening the mucus at the neck of the womb and thickening the uterine lining. It is very important to have an honest conversation with your doctor about using the pill, as there are circumstances in which it is less effective or shouldn’t be taken. These include if you are over 35 and smoke, if you suffer from certain medical conditions, or if you take certain medications. There is a chance you will get pregnant any time within the first month after you stop using the pill, but it could take up to three months.

This article was written as a jumping-off point for your personal research. It is very important to be fully informed about any form of contraception you use, including contraindications, any information about side effects, and how your choice may impact your health in later life. Practising safe sex is an important part of your own self-protection, as well as optimising your health for when you want to conceive a baby. Be sure to use any of the birth control mentioned in this article in conjunction with condoms if you are having sex with multiple partners or a partner who has not been STI tested. Be sure, be safe, and prioritise your health.

Contraception: Can I get pregnant with an IUD, ring, implant, IUS, or on the pill?

Unii looks at how likely you are to get pregnant while using various forms of birth control.