This is an updated guideline from the FSRH on emergency contraception. The fundamentals of this are not new, but there were quite a lot of things that I wasn't aware of or had forgotten. There are 2 really useful algorithms in the guideline and I have added these to the end of this summary. These really sum up everything you need to know.
How do the various methods work?
- Copper IUD (Cu-IUD) works by both inhibiting fertilisation and also be reducing the chance of implantation.
- Ulipristal acetate (UPA-EC or ellaOne) works by delaying ovulation for 5d (ie until sperm are no longer viable).
- Levonelle (Levonorgestrel) also works by delaying ovulation. It does not work in the few days before ovulation.
This is the most effective option and also provides ongoing contraception. It should be offered to all women. If women are being referred on for it, then offer oral emergency contraception (EC) immediately, in case the Cu-IUD can't be fitted in time.
It can be used on up to day 5 after the presumed date of ovulation (oral EC would not be effective after ovulation). If the first UPSI in a natural cycle has taken place after ovulation, then the Cu-IUD can be placed up to 5d after this UPSI. The 5d ruling is to ensure that the Cu-IUD is not placed after implantation.
Ulipristal acetate (ellaOne)
UPA-EC is effective for up to 120 hrs after UPSI.
It is more effective than Levonelle. It should be offered ahead of Levonelle if UPSI has taken place in the 5d before the presumed ovulation as Levonelle is then ineffective.
UPA-EC could be less effective if progesterones are taken less than 5d after it's use. It is possible that it is less effective if progesterones have been taken in the 7d before its use. This could therefore affect the woman's choice if they have been using hormones or if they want to quick start contraception. If the risk from this episode of UPSI is low (ie not within 5d of the likely date of ovulation), then a woman may wish to prioritise quick starting contraception.
Breastfeeding - Women should express and discard all milk for a week after UPA-EC is used and should not breastfeed.
Levonelle is licensed for use up to 72 hrs after UPSI and is ineffective 96 hrs after UPSI. It is not effective after ovulation, nor during the follicular phase (ie just before ovulation).
Other useful points:
- BMI - higher BMI (over 26) or weight (over 70kg) may make oral EC less effective - especially for Levonelle. Therefore UPA-EC should be used ideally, or otherwise a double (3mg) dose of Levonelle.
- Breastfeeding - Levonelle is safe with breastfeeding. If the woman prefers UPA-EC then she should not breastfeed for 1w and should express and discard all milk instead.
- Enzyme inducing drugs - could reduce the efficacy of oral EC. Ideally a Cu-IUD would be used. A double dose (3mg) of Levonelle could be used. You can't use a double dose of UPA-EC. It is not known whether a double dose of Levonelle is more effective than using UPA-EC.
- UPSI after ovulation - oral EC is not effective, so the Cu-IUD must be considered.
- UPSI more than once in a cycle - Levonelle and UPA-EC can be used even if there has been previous UPSI. Evidence suggests that they do not disrupt a pregnancy and would not cause fetal abnormality. Beware that if UPA-EC has been taken in the preceding 5d, that Levonelle should not be taken as it could reduce the efficacy of the UPA-EC. Similarly, if Levonelle has been taken in the last 7d, then UPA-EC could be less effective.
- Improper use of contraception - the guideline has a helpful chart listing all the forms of contraception and under which circumstances EC may be considered. Useful if in doubt.
- STDs - remember to give advice about STD screening.
- Pregnancy testing - do a pregnancy test if the woman has not had a normal period in the last 21d and has had prior UPSI since the last normal period. Advise women to do a pregnancy test if their period is late. Most women will have their period within 7d of the expected date.