If you have unprotected sex, then if you take an emergency contraceptive pill (sometimes known as the morning after pill) within a few days you have a good chance of preventing pregnancy. Alternatively, an intrauterine contraceptive device (IUCD) can be inserted up to five days after having unprotected sex.
What is emergency contraception?
There are three types of emergency contraception now available to women. These are two types of pill, and the intrauterine contraceptive device (IUCD) - also called the coil. They are available from your GP practice, NHS walk-in centres, family planning organisations (like British Pregnancy Advisory Service or Brook) and pharmacies.
Emergency contraception can be used:
- If you have had sex without using contraception.
- If you have had sex, but there was a mistake with contraception. For example, a split condom or if you forgot to take your usual contraceptive pills.
The progestogen pill
This is a pill that contains levonorgestrel which is a progestogen hormone. The brand name is Levonelle®. You can get it free on prescription or you can buy it from pharmacies, without a prescription. The usual dose is one pill which contains 1.5 mg of levonorgestrel. (Some women need a higher dose if they are taking certain other medication - for example, women taking certain anti-epilepsy medicines.)
When do I take it and how does it work?
Take the pill as soon as possible after unprotected sex. The earlier you take the pill, the more effective it is. It is thought to work either by preventing or delaying ovulation (the release of an egg each month) or by preventing the fertilised egg from implanting (settling) in the uterus (womb). It is not thought to cause an embryo, that is already implanted into the womb, to abort.
How effective is the progestogen pill?
Although emergency contraception is effective, it is not as reliable as regular planned contraception. Therefore, it should only be used in emergencies. The progestogen pill becomes gradually less effective the more time elapses after having unprotected sex. However, there is a good chance of preventing pregnancy if it is taken up to 72 hours after unprotected sex.
- If this pill is taken within 24 hours after unprotected sex, about 95 in 100 pregnancies are prevented.
- If it is taken between 25-48 hours after unprotected sex then about 85 in 100 pregnancies are prevented.
- If it is taken between 49 and 72 hours after unprotected sex, then about 58 in 100 pregnancies are prevented.
It is sometimes used between 72 and 120 hours after unprotected sex but the chance of it working is much less than if it is taken within 72 hours.
Are there any side-effects with the emergency progestogen pill?
Side-effects with the emergency progestogen pill are uncommon. However, some women feel sick for about 24 hours after taking the pill and a few vomit. This may be less likely to happen if you take the pill with food.
If you vomit within three hours of taking the pill then:
- take another pill as soon as possible. (You may need to get a further prescription, or buy another pill from the pharmacy. You may also wish to get a prescription for some antisickness tablets.) OR
- a coil (IUCD) can be inserted (see below).
Other mild side-effects occur in some women for a short time, such as abdominal pain, headache, tiredness, dizziness and breast tenderness.
Who should not take the emergency progestogen pill?
The vast majority of women are able to take the progestogen emergency pill. However, it is not suitable for all women. For example, women with a rare condition called porphyria should not take it.
If the pill did not work and you became pregnant, there is no evidence that taking the emergency progestogen pill is harmful to the baby.
Ulipristal acetate (also called ellaOne®) is a type of emergency contraceptive pill that was launched in the UK in 2009. It is taken as one single tablet.
When do I take it and how does it work?
Take the pill as soon as possible after unprotected sex. The earlier you take the pill, the more effective it is. It can be taken up to 120 hours (five days) after having unprotected sex. It is a type of hormone which seems to work by stopping or delaying release of an egg. It may also have an effect on the lining of the uterus (endometrium).
How effective is ulipristal?
Although emergency contraception is effective, it is not as reliable as regular planned contraception. Therefore, it should only be used in emergencies. It is most effective if you take the tablet as soon as you can, after having unprotected sex. The effectiveness decreases the longer you leave before taking the tablet.
One recent study looked at over 800 women who had received ulipristal. Ulipristal prevented over 98 out of 100 pregnancies. This study showed that ulipristal is actually more effective than the progestogen emergency pill.
Who should not take ulipristal?
Ulipristal cannot be taken if there is any possibility that you might be pregnant. It also cannot be taken if you have certain liver diseases or have severe asthma. You should not breast feed for one week after taking this tablet. Ulipristal can also interfere with certain medications, including rifampicin, phenytoin, and carbamazepine.
In addition, some medications taken for indigestion or heartburn (such as omeprazole or ranitidine) can interfere with the effectiveness of ulipristal. Your doctor will be able to give you more information about this.
It is currently only available if you are aged 18 or over.
Are there any side-effects of ulipristal?
Side-effects with the ulipristal pill are uncommon. These can include headaches, feeling sick, abdominal pains and irregular vaginal bleeding.
If you vomit within three hours of taking ulipristal then you will need to take another tablet. You will need another prescription for this.
Some reasons why the emergency contraception pills are less likely to be successful
- If you take the progestogen pill more than 72 hours or the ulipristal pill more than 120 hours after unprotected sex.
- If you vomit within three hours of taking the pill and do not take a repeat dose.
- If you also had unprotected sex at an earlier time.
- If you have unprotected sex again after taking emergency contraception.
The intrauterine contraceptive device (coil)
An alternative method of emergency contraception is to have an IUCD (coil) inserted by a doctor or nurse. This can be done up to five days after unprotected sex. It has the advantage of providing ongoing contraception and is also more effective than taking hormone tablets (it is almost 100% effective).
Most women can use the coil. Exceptions include those who have copper allergy or have had a heart infection called endocarditis.
See separate leaflet called 'Intrauterine Contraceptive Device' for details.
Some other points about emergency contraception
- Most women have their next period at about the usual time. Sometimes it is a few days earlier or later than expected. See a doctor or nurse if your next period is more than seven days late or if it is lighter than usual. A pregnancy test may be advised.
- Your next menstrual cycle may also be shorter or longer than usual.
- There is still a small risk of pregnancy even if you use an emergency contraceptive correctly.
Follow-up after receiving emergency contraception
You may want to discuss your regular contraceptive needs with a doctor or nurse. This may be best in a relaxed follow-up consultation.
An important message
See a doctor urgently if you have any lower abdominal pain or abnormal vaginal bleeding over a period of 2-6 weeks following use of emergency contraception. These are the main symptoms of an ectopic pregnancy. This is rare, but it is best to be aware of the possibility as it is a serious condition. Also, see a doctor if your next due period is more than seven days late or if you have any other concerns.
Your GP, practice nurse and pharmacist are good sources of information if you have any queries. The fpa (formerly the family planning association) also provides information and advice. fpa's Helpline: 0845 310 1334 or visit their website www.fpa.org.uk
Further reading & references
- Drug Interactions with Hormonal Contraception, Faculty of Sexual and Reproductive Healthcare (2011)
- Contraception - emergency, Prodigy (March 2011)
- Emergency Contraception, Faculty of Sexual and Reproductive Healthcare (2011)
- Ulipristal Acetate (ellaOne®); Ulipristal Acetate (ellaOne®), New Product Review, Faculty of Sexual and Reproductive Healthcare (2009)
- Glasier AF, Cameron ST, Fine PM, et al; Ulipristal acetate versus levonorgestrel for emergency contraception: a Lancet. 2010 Jan 28.
|Original Author: Dr Louise Newson||Current Version: Dr Hayley Willacy||Peer Reviewer: Dr Hannah Gronow|
|Last Checked: 24/01/2012||Document ID: 4539 Version: 43||© EMIS|
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