Pills to stop pregnancy after 72 hours

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Cet article est disponible en français. Voyez "La contraception d’urgence : La prévention d’une grossesse après une relation sexuelle".

You can become pregnant if you have unprotected intercourse even just once! Emergency contraceptive pills (ECPs) can prevent pregnancy. The ECP should only be used in an emergency. It only works for a short period of time.

When should I use the ECP?

The ECP is best used within three days (72 hours) after unprotected sex. Some doctors will prescribe it up to five days, but there is less evidence about how well it works then. The sooner you take the ECP, the better it will work. Unprotected sex includes:

• When no birth control was used.

• When birth control may have failed. For example:

  • – If a condom broke or slipped.

  • – If a diaphragm or cervical cap came off, tore or was taken out too early.

  • – If you missed taking two or more of your birth control pills or started a new pack three or more days late.

  • – If you were late for your birth control shot.

• When you have been abused, sexually assaulted or raped and are not already using a reliable method of birth control.

Although sometimes called the morning-after pill, emergency contraception has been proven to be effective up to three days after intercourse. It does not have to be taken in the morning.

How well does the ECP work?

If 100 women have unprotected sex just one time, eight of them will get pregnant. Using the ECP, one to three will get pregnant.

The ECP is only for emergencies. It is not a good form of regular birth control. Things that work better include the birth control pill, the shot or the needle (Depo-Provera [Pharmacia & Upjohn Inc, Mississauga]), an intrauterine device (IUD), condoms or abstinence (not having sex).

The ECP won’t protect you against sexually transmitted infections. If you are worried about sexually transmitted infections (STIs), please talk to your doctor or visit a clinic.

What is the ECP?

ECPs are made of the same hormones as birth control pills. Some have only one hormone (called Plan B) and some have two (called the Yuzpe method). See Table 1 for a comparison of the two types.

TABLE 1

Yuzpe MethodPlan BChance of getting pregnant cut by 75%Chance of getting pregnant cut by 85%More nausea and vomitingLess nausea and vomitingCosts about $15 to $20Costs about $30 to $35

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Is the ECP safe?

Yes. The ECP is only used for a short time, and the amount of hormones in the ECP is low.

One group that found the ECP to be safe is the World Health Organization. They say that the ECP is extremely safe and can be safely used to prevent pregnancy.

If you have ever had blood clots, a stroke or a heart attack, you should only use the ECP called Plan B. It is made with only one hormone, progestin.

What if I am already pregnant?

Emergency contraception will not make your pregnancy go away. It is not an abortion pill. However, if you find out after you have taken it that you are pregnant, it will not harm the fetus. Many women have taken estrogen and progesterone (the hormones in ECPs) in early pregnancy and have gone on to have normal babies. If you find out you are pregnant, you should discuss your options with a health care provider as soon as possible.

What are the side effects of emergency contraception?

The most common side effects of ECPs are nausea and vomiting, especially with the Yuzpe method. If your doctor gives you this form of ECP, they will also give you medication to prevent vomiting. If you throw up within an hour of taking the first dose of ECPs, you need to take more ECPs. Some women also have tender breasts, bloating, irregular bleeding, and headaches. These do not last long.

How do I use the ECP?

Either kind of ECP comes in two doses. Take the first one as soon as possible. Take the second one 12 hours later.

The first dose must be taken within 72 hours (three days) after unprotected sex (it could be five days according to your doctor’s prescription). The sooner you take the ECP, the better it will work.

If you throw up within 1 hour of taking the pills, you need to take another dose.

If you are given a pill to prevent nausea (always given with the Yuzpe method) do not drive or drink any alcohol for 36 hours after the first set of pills. The medication that you take to prevent nausea may make you feel drowsy.

Do not take any extra birth control pills. They will not decrease your chance of getting pregnant and will make you feel sick.

What if it’s too late for the ECP?

If it is too late for you to take the ECP, an IUD may cut the risk of pregnancy. An IUD may work if you had unprotected sex within the past seven days.

What should I do until my next period?

The ECP will not last until your next period. If you are not taking a regular form of birth control, you should use condoms and foam if you have sex.

If you are already taking oral contraceptives (the pill) but have missed some pills, start a new pack of pills the day after you take the ECP. The use of a condom is essential to prevent STIs.

If you want to start oral contraceptives or Depo-Provera (the injection), wait until your next period starts and use condoms and foam until then.

Your next period may be a little early or a little late; however, most women get their next period at about the regular time. If you don’t have a normal period within three weeks after taking the ECP, you should have a pregnancy test to make sure you aren’t pregnant.

Why not just use emergency contraception each time I have sex?

Emergency contraception is not as good at preventing pregnancy as other methods of birth control such as birth control pills taken regularly or birth control shots. In addition, you should be using condoms to prevent STIs such as human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS).

Where can I find more information?

Your paediatrician, family doctor, pharmacist or local public health department will have more information about this topic. In some provinces, pharmacists can give out emergency contraception without a prescription. On the Internet, you can try ec.princeton.edu or look for the Canadian Paediatric Society (CPS) position statement on emergency contraception prepared by the Adolescent Health Committee on the Society’s Web site.

Footnotes

This information should not be used as a substitute for the medical care and advice of your physician. There may be variations in treatment that your physician may recommend based on individual facts and circumstances.

Internet addresses are current at time of publication.

May be reproduced without permission and shared with patients and their families. Also available at www.caringforkids.cps.ca

Canadian Paediatric Society, 2204 Walkley Road, Suite 100, Ottawa, Ontario K1G 4G8, telephone 613-526-9397, fax 613-526-3332, Web site www.cps.ca

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