Part of the TeachMe Series

Emergency Contraception

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Original Author(s): Wes
Last updated: 7th April 2022
Revisions: 11

Original Author(s): Wes
Last updated: 7th April 2022
Revisions: 11

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Emergency contraception is used to prevent pregnancy following sexual intercourse (in contrast to other forms of contraception, which are used either before or during sex).

This article covers the main methods of emergency contraception, along with their benefits, risks and some wider considerations.


There are two key indications for emergency contraception:

  • Sexual intercourse without contraception, or
  • Contraceptive method has failed (e.g. a condom has torn).

For women using either the combined or progesterone only OCP, there may be a requirement for emergency contraception depending on how many pills have been missed.

Types of Emergency Contraception

In the UK, the two forms of emergency contraception are the ‘morning after pill’ and the intrauterine device (IUD).

Emergency Hormonal Contraception (‘Morning After Pill’)

There are two types of emergency hormonal contraception currently available within the United Kingdom:

  • Levonorgestrel (1.5mg tablet) – Synthetic progesterone (marketed as Levonelle One Step, amongst others).
    • Current evidence indicates that it can delay ovulation for 5 to 7 days, after which any sperm will have become non-viable. Licensed for use within 72 hours of unprotected sex.
  • Ulipristal acetate (30mg tablet) – Progesterone receptor modulator (marketed as EllaOne).
    • Current evidence indicates that it can delay ovulation for 5 to 7 days, after which any sperm will have become non-viable. Licensed for use within 120 hours of unprotected sex.

Both contraceptive pills have no known effect on disruption/inhibition of implantation. Their principle effect is due to inhibition of ovulation.

The Intrauterine Device

The copper intrauterine device (commonly abbreviated to Cu-IUD) is usually used a method of long term non-hormonal contraception, but when it is inserted within 5 days of unprotected sex, it may be used as emergency contraception.

The copper within the coil is toxic to sperm, and it may induce a sterile inflammatory response within the uterus that makes implantation impossible. It remains in situ and provides contraceptive cover for five to ten years, depending on the type. Due to this, it is the only method of emergency contraception that provides protection past the initial administration.

This method is over 99% effective and should be offered to all women presenting for emergency contraception.

Fig 1 Positioning of the IUD

Fig 1 Positioning of the IUD



There are no absolute contraindications to the use of levonorgestrel, however efficacy may be reduced by:

  • Diseases of malabsorption e.g. Crohn’s
  • BMI > 26 or weight >70kg
  • Enzyme inducing drugs e.g. rifampicin
    • If patient refuses IUD, then double dose i.e. 3mg at once may be taken

Ulipristal Acetate

  • Diseases of malabsorption e.g. Crohn’s
  • Hypersensitivity to Ulipristal Acetate
  • Severe hepatic dysfunction
  • Enzyme inducing drugs e.g. rifampicin
    • Give 3mg levonorgestrel if the patient refuses an IUD, ulipristal acetate is absolutely contraindicated here
  • Breast feeding – avoid breastfeeding for 7 days after taking UPA
  • Asthma insufficiently controlled by corticosteroids
  • Drugs increasing gastric pH e.g. omeprazole, ranitidine

Copper IUD

  • Uterine fibroids with distortion of the uterine cavity
  • Documented or suspected pelvic inflammatory disease (PID)
  • Documented or suspected STI (especially chlamydia or gonorrhoea)

Follow Up/Adverse Effects

Emergency Hormonal Contraception

As always, follow up advice should be provided in both verbal and written forms. Advise patient to seek help if vomiting occurs within 2 hours of taking levonorgestrel or 3 hours of taking ulipristal as the medication may not have been absorbed adequately.

Also advise that only the IUD affords protection for the rest of the cycle (and onwards). All patients should be advised that effectiveness of hormonal methods declines as time since the sexual intercourse increases.

Adverse effects of emergency hormonal contraception include nausea, dizziness, menstrual disturbance and abdominal pain. Consider a pregnancy test no sooner than 3 weeks after unprotected intercourse to exclude pregnancy.

The Intrauterine Device

Patients should be advised of the increased relative risk of ectopic pregnancy following insertion of an IUD and to be alert if her next period is >5 days late with reduced bleeding, especially coupled with severe lower abdominal pain.

If a pregnancy test is positive, an urgent ultrasound scan is required to locate the pregnancy.

Adverse effects of the IUD include pelvic infections, expulsion (of the IUD), bleeding and pelvic pain.

Key Points to Consider

  • Treat the patient in a non-judgemental fashion.
  • Patient should be offered a full screen for STIs (if the setting is appropriate e.g. GUM clinic), and should be tested for chlamydia as a minimum when inserting an IUD.
  • Patients under 16 may be prescribed emergency contraception provided they meet the Fraser criteria.
  • Was sexual intercourse consensual and non-coercive? Consider child protection or vulnerable adult referrals if concerned about abuse. Children aged 12 or under are not considered legally able to consent to sexual activity and should be automatically referred to the safeguarding team.
  • Offer long term contraception after using levonorgestrel or ulipristal acetate and discourage use of the morning after pill as regular contraception.