The Faculty of Sexual and Reproductive Healthcare (FSRH) Clinical Guidance for Emergency Contraception summarises the available evidence on emergency contraception (EC).
Important points from this guidance are:
- A copper intrauterine device (Cu-IUD) is the most effective method of EC and is not known to be affected by weight or BMI.
- Ulipristal has been demonstrated to be more effective than levonorgestrel.
- Ulipristal acetate EC (UPA-EC) can be effective for EC up to 120 hours after unprotected sexual intercourse (no contraception used or contraception used incorrectly) (UPSI).
- Levonorgestrel EC (LNG-EC) is licensed for EC up to 72 hours after UPSI. The evidence suggests that LNG-EC is ineffective if taken more than 96 hours after UPSI.
- It is possible that higher weight or BMI could reduce the effectiveness of oral EC, particularly LNG-EC.
- Enzyme-inducing drugs could also reduce the effectiveness of UPA-EC and LNG-EC.
- Available evidence suggests that oral EC administered after ovulation is ineffective.
All women requiring emergency contraception should be offered a Cu-IUD if appropriate as it is the most effective method of contraception. In many cases it is appropriate to provide emergency contraception as immediate treatment, as well as referring for a Cu-IUD.
Further information is available at the NHS Lanarkshire Sexual Health website.
The FSRH advises to quick-start on-going method of contraception which means starting a method immediately after the administration of emergency contraception (EC).
A method that has been quick started may be continued as an ongoing method of contraception or it may be used as a temporary ‘bridging’ method until pregnancy can be excluded and a longer-acting method initiated.
The decision to start a contraceptive method immediately after progestogen-only emergency contraception (POEC) should be considered on an individual basis.
For further information on quick-starting contraception and the effect of EC on this please refer to FSRH Clinical Guidance for Quick Starting Contraception.