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Emergency contraception is an important post-coital method of contraception to prevent pregnancy from occurring.
These methods do not cause abortion. Instead, they prevent ovulation, fertilisation, and/or implantation. There are three methods by which this can occur, although in reality, only the first two are widely used.
  • Oral progesterone-only emergency contraception (POEC) – levonorgestrel
  • Copper intra-uterine contraceptive device (IUD)
    • Intra-uterine device is the most effective method, and should be offered to all women, even this presenting after 72 hours
    • The IUS (intrauterine system) aka progesterone containing intrauterine system (e.g. mirenais NOT indicated
  • Selective progesterone receptor modulator (SPRM) – ulipristal acetate (UPA)
In the UK, the emergency contraceptive pill (levonorgestrel) is provided free of charge at most health care centres (e.g. GUM clinics, GP’s). You can also buy it at most pharmacies, if you are over 16 (~£25) without a prescription.

Assessment and History

  • Document date of LMP (last menstrual period)
  • Ask about:
    • Timing of unprotected sexual intercourse
      • If >72 hours – IUD recommended, <72 hours either IUD or levonorgestrel
    • Current contraceptive methods
      • If on the pill, ask about missed pills
      • May be appropriate to talk about proper use of barrier methods and assess if they are being used correctly
    • Possibility of non-consensual sex and offer support and referral if appropriate
  • Remember: there is no time in the menstrual cycle where there is no risk of pregnancy. The risk is lowest in the first 3 days. 
  • Important to advise the patient that:
    • Methods are not 100% effective
    • Their next period may be early or late
    • They should have a pregnancy test if their next period is >7 days late
    • They should see a doctor immediately if they develop lower abdominal pain
    • They should consider ongoing long-term contraceptive options
    • Discuss the risk of STI – and consider sexual health screening

Emergency oral preparations

More effective the sooner they are taken.


The same progestrogen found in the IUS. It is a progestrogen only pill. Thus it is safe in breastfeeding, and for women in whom oestrogens are contraindicated.

Dose – 1.5mg

  • Consider 3mg dose if raised BMI or on liver-enzyme inducing medications


  • Severe liver disease
  • Known allergy to levonorgestrel

Side effects

  • Menstrual irregularities
  • For most women the next period will be normal, but it can be 2-7 days late.
  • There may be irregular bleeding during the next menstrual cycle
  • Nausea
  • Vomiting
  • Breast tenderness


  • Most effective within 12 hours after sexual intercourse
  • 95% if <24h
  • 85% if 24-48h
  • 58% if 49-72h
  • May be given up to 120h, but is not recommended. Between 72-120h, an IUD is recommended as it is more effective


  • If vomiting occurs within 2 hours of administration, another pill should be given. If vomiting continues, consider IUD, or consider another dose, with an antiemetic (domperidone recommended).


Can be taken as many times as necessary, even within the same menstrual cycle however, not recommended, as it is not as reliable as regular contraception.

A barrier method of contraception needs to be used for 7 days (COCP), or 3 days for POCP.

  • If due to missed oral contraceptive pill advise to take the next one within 12 hours of taking levonorgestrel – but re-iterate she will need to use barrier contraceptive for the time periods outlined above

If there is any lower abdominal pain before the next period, she should consult immediately to rule out ectopic pregnancy
If she has any concerns (e.g. if next period is late, could be pregnant) to seek medical advice.

Ulipristel Acetate

  • Not regularly used in the UK
  • Contraindicated in uncontrolled asthma
  • Reduces efficacy of COC and POP
  • Should not be used more than once in one menstrual cycle
  • Avoid breast-feeding for 36 hours (precautionary, no evidence)
  • Cannot be used in pregnancy – do a pregnancy test before prescribing
  • 30mg as soon as possible after intercourse. Should not be used >120 hours after intercourse
  • The only oral method licensed for use between 72 and 120 hours
  • Side effects – GI disturbance, dizziness, fatigue, headaches, menstrual irregularities

IUD as emergency contraception

  • More effective than levonorgestrel – around 99% effective
  • Copper has multiple effect on the fertilisation and implantation process
    • Inhibits sperm penetration of cervical mucus
    • Toxic effects on the ovum
    • Inflammatory reaction effects on the endometrium prevent implantation
  • Effective up to 5 days after intercourse
    • Ensure that the patient has only had unprotected sex once since the last period – if not, the IUD is only effective if fitted within 5 days of the earliest date of ovulation.
  • Also provides ongoing contraception
  • Efficacy – 99% effective
  • Risk factors and side effects – same as the IUD in normal circumstances
    • Remember; risk of infection within 20 days of fitting, and increased risk of PID.
  • Fitting – same as IUD in normal circumstances, except:
    • Swabs for STI recommended to be taken in all instances
    • Antibiotic prophylaxis may be given at the time of insertion if deemed to be high risk for PID: age <=25, new sexual partner, >1 sexual partner in last 12 months
  • Next period – should be at the normal time
  • Follow up –same as UD in normal circumstances. Check up at 3-6 weeks. IUD can then be removed if the patient does not wish to use it as a form of long term contraception


Those who believe life begins at fertilisation may argue that abortion can occur with these methods, and may have moral objections. However, the methods do not cause any alteration to an embryo after implantation.

  • In the UK, a 2002 Judicial Review concluded that – legally – life begins at implantation and not at fertilisation.


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