Chapter 2
Emergency contraception
Contents
Information to elicit if a woman presents for hormonal EC
Vomiting after taking a dose of hormonal EC
Women using liver enzyme inducing medications
Non-liver enzyme inducing antibiotics
Ulipristal acetate emergency contraception
Emergency contraception (EC)
EC is sometimes referred to as post-coital contraception. It is a safe way to reduce the risk of pregnancy after unprotected sexual intercourse (UPSI), sexual assault or potential contraceptive failure.
EC methods do not cause disruption to an established pregnancy; that is, they do not result in an abortion.
Methods available
Hormonal EC
Hormonal EC is sometimes, misleadingly, referred to as the morning after pill.
Levonorgestrel EC (LNG-EC)
- 1.5 mg stat LNG (first-line preferred hormonal method)
Yuzpe method
- combined oestrogen and progestogen (second-line and used rarely if LNG-EC is not available)
Non-hormonal EC
Copper-IUDs (Cu-IUDs)
These are an extremely effective EC method with the advantage of providing immediate and ongoing contraception.
Cu-IUDs inserted post-coitally can be used as an effective form of ongoing contraception.
EC access
Hormonal EC access
LNG-EC is available over the counter at a pharmacy (S3) without a prescription. Most Australian women are aware of EC but more than 50% are unaware that it is available without prescription.(1)
Cu-IUD access
Services able to provide IUD insertion within a short timeframe have been limited in Australia, making this a rarely used option. Its availability may increase in the future if more practitioners receive appropriate training in IUD insertion.
EC and young women
There is no legal lower age limit for prescription or over the counter (non-prescription/S3) dispensing of LNG-EC, provided the woman is assessed as a mature minor – refer to the consent to treatment section. However, in general over the counter supply of S3 medications is regulated by state laws. Practitioners should check their state and territory based legislation for further details. Where interpretation of state based regulations limits over the counter supply to young people a prescription is required and can be provided in advance.
EC advanced supply
Many women, including those using barrier contraception or those travelling to places with limited LNG-EC access, would benefit from advanced supply. Women who have an advanced supply of LNG-EC are more likely to use it (2) and to use it in a timely manner.(3)
Some women, particularly young women, face or perceive barriers to obtaining LNG-EC over the counter.(4, 5, 6) Practitioners may consider supplying these women with a prescription for an advanced supply of LNG-EC.
Mechanism of action
LNG-EC
LNG-EC primarily acts to prevent or delay ovulation by interfering with follicular development. It appears to have no effect once the luteinising hormone (LH) surge has commenced. It does not prevent fertilisation or inhibit implantation once ovulation has occurred.(7, 8, 9)
Cu-IUD
Insertion of a Cu-IUD interferes with sperm movement, inhibits fertilisation by direct toxicity and may also prevent implantation of a fertilised ovum.(10) A LNG-IUD is not suitable for use as post-coital contraception.(10)
Effectiveness
The effectiveness of the method of EC is given as the estimated percentage of pregnancies prevented that would otherwise have occurred if no method were used:
Whilst LNG-EC is approved for use for up to 72 hours after UPSI, it has proven effectiveness for up to 96 hours (4 days). There is some evidence that effectiveness is improved the earlier the LNG-EC method is given in relation to coitus.(11) While there is no harm in giving LNG-EC up to 120 hours post-coitus, there is greater than a 5 times increase in risk of pregnancy on the fifth day compared to administration within the first 24 hours.(12)
LNG-EC does not increase the risk of an ectopic pregnancy. LNG-EC reduces the risk of pregnancy and if pregnancies do occur after using LNG-EC, the rate of ectopic pregnancy is not higher than what is otherwise expected.(20)
Multiple UPSI events in cycle
Hormonal EC may be used for each act of UPSI in any cycle. It should be repeated if UPSI occurs any time more than 12 hours after EC was taken.(17) The LNG-EC does not induce an abortion if the woman is already pregnant and there is no evidence that it harms a developing foetus (18, 19) but existing, established pregnancy should be excluded with a pregnancy test when relevant.
Dose and administration
Hormonal EC should be given as a single dose unless either 30mcg LNG pills or the Yuzpe method is used. These are given as 2 divided doses, 12 hours apart. There is no loss of effectiveness if the second dose is delayed, as long as it is within 24 hours of the first dose.(21)
LNG-EC
Stat dose:
Divided dose:
- 2 doses of 0.75 mgb of LNG taken 12 hours apart. Each dose could be made up of:
Yuzpe method
The Yuzpe method should be used only when there is no possibility of the woman obtaining a supply of LNG-EC.
- 2 doses are taken 12 hours apart with each dose containing at least 100mcg of ethinyloestradiol (EE) and 500mcg of LNG. An anti-emetic can be given with each dose.
Example: each of the 2 doses can be made by taking:
- 4 tablets of either Nordette®, Microgynon® 30 ED, Monofeme® or Levlen® ED or
- 5 tablets of either Microgynon® 20 ED, Loette® or Microlevlen® ED
Note: The only 50mcg EE pill available in Australia (Microgynon® 50 ED) does not contain sufficient LNG to be used for the Yuzpe method.
Cu-IUD
Procedure:
Assess the woman and her circumstances as per the guidelines for IUD pre-insertion consultation – see section on ‘History, Examination and Investigations’ here. Consult with or refer to an appropriately trained IUD health practitioner to assess client suitability for the insertion.
Timing:
Most women with a 28 day cycle will ovulate around Day 14. However, the timing of ovulation varies, including in those with predictable cycles.(22) To completely exclude the possibility of an existing implantation, instructions for timing of insertion are based on very conservative estimates. Day 7 is used as the earliest day of fertile ovulation and 5 days are allowed for implantation.
General guidelines for insertion
Insert up to Day 12 of the cycle or within 5 days of the first episode of UPSI for the cycle, whichever is later.
For example:
a) Deborah is at Day 11 of her menstrual cycle and has had UPSI 3 times since Day 1 of her cycle (the first day of bleeding):
She can have a Cu-IUD inserted today or tomorrow, since this will prevent pregnancy and provide ongoing contraception.
b) Kathy is at Day 20 of her menstrual cycle and had intercourse on Days 7 and 15 of her cycle:
She is already at risk of a pregnancy from the sex on Day 7 so should not have a Cu-IUD inserted in this cycle.
c) Caroline is at Day 20 of her menstrual cycle and had sex on Days 16, 17 and 19 of her cycle:
She can have a Cu-IUD inserted today since she is within 5 days of the first episode of UPSI this cycle.
Further information
These general guidelines may exclude a number of women from a safe emergency Cu-IUD insertion. The following alternative guidance may be considered when the inserting clinician is reasonably certain about the timing of ovulation:
Insert up to 5 days after the earliest predicted ovulation or within 5 days of the first episode of UPSI for the cycle, whichever is later. For example:
Margot is at Day 17 of her menstrual cycle, which is always 28–30 days in length. She has had UPSI 3 times since Day 1 of her cycle (the first day of bleeding):
She is aware of her cycle and gets mucus changes and pain that help her recognise ovulation. She thinks she ovulated on Day 14 of this cycle. She can have a Cu-IUD inserted (as EC and ongoing contraception) today or tomorrow since it is reasonably certain that she ovulated in the past 5 days.
Contraindications
Hormonal EC
The LNG-EC has no evidence based contraindications except for allergy and a known pregnancy (although the LNG-EC is not considered harmful to an existing pregnancy). It can be used by women of any age who are at risk of an unintended pregnancy.d
Cu-IUD
The eligibility criteria for regular use of Cu-IUDs generally apply to emergency use. See the section on medical conditions and the use of IUDs for contraindications.
Practice point
It is important to consider continuing effective contraception, as LNG-EC provides no ongoing protection against pregnancy.
Table 2.1: A summary of significant UK Medical Eligibility Criteria (UKMEC) 2009 for hormonal EC (23, 24)
– refer to Chapter 12 for full details of all eligibility criteria and Chapter 1 for information on using UKMEC.
| Medical Eligibility Criteria | Medical conditions |
| Category 4 | Absolute contraindication |
| A condition that represents an unacceptable health risk if the contraceptive method is used | There are no evidence based absolute contraindications to hormonal EC except established pregnancy and allergy to its components. |
| Category 3: | Strong relative contraindication |
| A condition where the theoretical or proven risks usually outweigh the advantages of using the method | There are no evidence based strong contraindications to hormonal EC |
| Category 2: | Generally safe to use |
| Conditions where the advantages generally outweigh the risks |
|
| Product Information (PI) for LNG-EC states that if a woman has had UPSI more than 72 hours earlier in the same menstrual cycle, conception may have already occurred. Treatment with Postinor-1 following the second act of intercourse may therefore be ineffective in preventing pregnancy. While the consensus is that levonorgestrel is not teratogenic, no guarantee can be given that pregnancy will result in a normal baby. The results of a prospective cohort study done in 2009 revealed that there was no association between the use of LNG-EC pills and the risk of major congenital malformations, pregnancy complications or any other adverse pregnancy outcomes.(19) In line with WHO and other international groups this is not considered a contraindication. |
|
Table 2.2: Advantages and disadvantages of EC types
| Method | Advantages | Disadvantages |
| LNG-EC |
|
|
| Cu-IUD |
|
|
| COC (Yuzpe) |
|
|
Side effects
LNG-EC
General side effects
- headache, nausea and altered bleeding patterns
- vomiting occurs in approximately 1%
Altered bleeding patterns after hormonal EC
Menstrual disturbance is common after hormonal EC.
- Most women have a menstrual bleed within 7 days of their expected time; bleeding may occur a few days earlier or a few days later than expected.(25)
- It can be difficult for women to differentiate between non-menstrual bleeding after hormonal EC, breakthrough bleeding (BTB) due to missed pills and normal menstruation.
- A follow up pregnancy test 3 weeks after UPSI may be important to exclude pregnancy.
Cu-IUD
See Chapter 4 for risks and side effects associated with Cu-IUD use.
EC use and future fertility
The use of EC is not associated with a decrease in future fertility.
Information to elicit if a woman presents for hormonal EC
- What is the risk of conception with this episode of intercourse? (may include date of last normal menstrual period (LNMP), timing of intercourse in relation to LNMP, history of failed contraception including missed pills or broken condom)
- What is the risk of a pre-existing pregnancy? (may include nature and timing of LNMP, previous episodes of UPSI this cycle)
- Is there current use of liver enzyme inducing medications? (such as carbamazepine – see Table 11.9 here)
Further useful information
- Is there a current risk of an STI?
- What are the woman’s ongoing contraceptive needs?
No examination is necessary unless a Cu-IUD insertion is planned − see here.
The following investigations may be useful depending on the woman’s circumstances:
- a pregnancy test, but only if there is a concern about a pre-existing pregnancy (note that a urine pregnancy test which is sensitive to a beta hCG level of 25mIU/ml carried out any less than 21 days after UPSI may give a false negative result. A pregnancy test should be interpreted in conjunction with menstrual and sexual history – see section ‘Considering the Risk of Pregnancy’ here
- a chlamydia screening test if the woman is at risk of infection; opportunistic annual screening is advised for sexually active women less than 25 years of age, regardless of risk assessment (26) – chlamydia screening should ideally occur at least a week after UPSI but may be carried out earlier if this presents the only opportunity for testing, as it may detect pre-existing infection
- other STI screening as indicated by the history should be carried out within appropriate timeframes
Return for review
Hormonal EC
Review is usually not necessary after administration of hormonal EC but is advised in some situations.
Advise a review with a pregnancy test in 3 to 4 weeks if:
- there is a high assessed risk of pregnancy when hormonal EC is given
- hormonal contraception is started immediately after taking EC (Quick Start method)
- hormonal EC has been used more than once this cycle
- the next menstrual period is more than 7 days late
- the next menstrual period is unusual in some way eg there is increased spotting before or after the period; the period is unusually light, painful or prolonged
Advise a review for STI testing in 2 to 3 weeks if an STI risk is identified or if symptoms consistent with an STI develop.
Review if a home pregnancy test is positive.
Cu-IUD
All women having had a Cu-IUD inserted for EC should return in 3 weeks for follow up including a pregnancy test, regardless of the onset of menstruation.
Management issues
Vomiting after taking a dose of hormonal EC
The dose of hormonal EC should be repeated (with the addition of an anti-emetic) if vomiting occurs within 2 hours of it being administered. Vomiting more than 2 hours after either dose is not considered to affect effectiveness.
Breastfeeding
Continued feeding is considered safe as the infant exposure to LNG is very small.(27) A Cu-IUD may be inserted as appropriate. Product Information (PI) for LNG-EC states that women should be advised not to breastfeed within 3 days after taking LNG EC, but this recommendation is not supported.
Repeated hormonal EC use
Repeated LNG-EC use may be effective but may result in disturbances in bleeding. There is no evidence of any serious harm caused by repeated use of hormonal LNG-EC.(28)
Women using liver enzyme inducing medications
- Women who are currently using a liver enzyme inducing medication can if practical, be advised to use a Cu-IUD. If a Cu-IUD is unavailable, a 3 mg dose of LNG-EC should be advised. Women who are within 28 days of stopping a liver enzyme inducing medication should also be advised to use a 3 mg LNG-EC dose (17) – see section on ‘Liver and gall bladder’ here.
- Women should take 2 × 1.5 mg or 4 × 0.75 mg LNG tablets stat for a total dose of 3 mg LNG.
- The Cu-IUD is the EC method of choice for women using a potent liver enzyme inducing medication, such as Rifampicin.
Non-liver enzyme inducing antibiotics
- There is no interaction between hormonal EC and non-liver enzyme inducing antibiotics.
Diarrhoea and malabsorption
LNG is absorbed in the duodenum, so consideration needs to be given only to conditions affecting small bowel absorption. A Cu-IUD is not affected and should be strongly considered if absorption is considered to be significantly impaired.
Table 2.3: Indications for EC when using another contraceptive method
| Method | EC indicated | Comment |
| Combined oral contraceptive (COC) pills (further information see here) |
|
|
| Combined vaginal ring (further information see here) |
|
|
| Progestogen only pills (POPs) (further information see here) |
|
|
| DMPA injection (further information see here) |
|
|
| ENG implants (further information see here) |
|
|
| LNG-IUD and Cu-IUD (further information see here) |
|
|
| Condoms – male and female (further information see here) |
|
|
| Diaphragm (further information see here) |
|
|
| Fertility Awareness Based Methods (FABMs) |
|
|
Ongoing contraception
A CHC or the POP can be started immediately after hormonal EC use (Quick Start regimens). The COC will be effective after 7 consecutive active pills and the POP after 3 consecutive pills. Pregnancy should usually be excluded before any long acting methods are initiated.
However, in high risk situations, particularly where a woman feels she would be likely to terminate a pregnancy, an implant or DMPA can be initiated immediately if the woman is informed that:
- pregnancy cannot be excluded
- there are no known teratogenic e effects but they cannot be excluded (31)
- she should use additional barrier contraception for 7 days
- she needs to return for a pregnancy test in 4 weeks regardless of vaginal bleeding
See here for further discussion on Quick Start.
Method failure
- exclude ectopic pregnancy
- assess gestation
- discuss pregnancy choices
EC in the future
Ulipristal acetate emergency contraception
Ulipristal acetate (UPA) has been available in Europe since 2009 as ellaOne®. It is a selective progesterone receptor modulator (SPRM) and is licensed as EC for up to 120 hours after UPSI or contraceptive failure. It works primarily in the same way as the LNG-ECP, by inhibiting or delaying ovulation but also may cause alteration to the endometrium. Research suggests it has superior effectiveness to the LNG-ECP at 24, 72 and 120 hours.(32)
UPA has a similar safety profile and side effects to LNG-ECP and its effectiveness is reduced by liver enzyme inducing drugs.
Its effectiveness also appears to be reduced by drugs which increase gastric pH including proton pump inhibitors and H2 receptor antagonists. It is more expensive than the LNG-ECP and is only available by prescription, rather than over the counter in the UK. Its safety has not been established for use more than once in a cycle and it may reduce the effectiveness of progestogen containing contraceptives used later in the cycle. Women who are breastfeeding are advised to avoid breastfeeding for 36 hours after administration.(17) UPA is not available in Australia at the time of publication.
References
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2. Raine TR, Harper CC, Rocca CH, Fischer R, Padian N, Klausner JD, et al. Direct access to emergency contraception through pharmacies and effect on unintended pregnancy and STIs: a randomized controlled trial. Jama. 2005;293(1):54–62.
3. Gold MA, Wolford JE, Smith KA, Parker AM. The effects of advance provision of emergency contraception on adolescent women’s sexual and contraceptive behaviors. J Pediatr Adolesc Gynecol. 2004;17(2):87–96.
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5. Hussainy SY, Stewart K, Chapman CB, Taft AJ, Amir LH, Hobbs MK, et al. Provision of the emergency contraceptive pill without prescription: attitudes and practices of pharmacists in Australia. Contraception. 2011;83(2):159–66.
6. Mohoric-Stare D, C DEC. Knowledge of emergency contraception amongst tertiary students in far North Queensland. Aust N Z J Obstet Gynaecol. 2009;49(3):307–11.
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8. Croxatto HB, Devoto L, Durand M, Ezcurra E, Larrea F, Nagle C, et al. Mechanism of action of hormonal preparations used for emergency contraception: a review of the literature. Contraception. 2001;63(3):111–21.
9. Noe G, Croxatto HB, Salvatierra AM, Reyes V, Villarroel C, Munoz C, et al. Contraceptive effectiveness of emergency contraception with levonorgestrel given before or after ovulation. Contraception. 2010;81(5):414–20.
10. Stanford JB, Mikolajczyk RT. Mechanisms of action of intrauterine devices: update and estimation of postfertilization effects. Am J Obstet Gynecol. 2002;187(6):1699–708.
11. Piaggio G, von Hertzen H, Grimes DA, Van Look PF. Timing of emergency contraception with levonorgestrel or the Yuzpe regimen. Task Force on Postovulatory Methods of Fertility Regulation. Lancet. 1999;353(9154):721.
12. Piaggio G, Kapp N, von Hertzen H. Effect on pregnancy rates of the delay in the administration of levonorgestrel for emergency contraception: a combined analysis of 4 WHO trials. Contraception. 2011;84(1):35–9.
13. Randomised controlled trial of levonorgestrel versus the Yuzpe regimen of combined oral contraceptives for emergency contraception. Task Force on Postovulatory Methods of Fertility Regulation. Lancet. 1998;352(9126):428–33.
14. Zhou L, Xiao B. Emergency contraception with Multiload Cu-375 SL IUD: a multicenter clinical trial. Contraception. 2001;64(2):107–12.
15. Wu S, Godfrey EM, Wojdyla D, Dong J, Cong J, Wang C, et al. copper T380A intrauterine device for emergency contraception: a prospective, multicentre, cohort clinical trial. BJOG. 2010;117(10):1205–10.
16. Trussell J, Ellertson C, Stewart F. The effectiveness of the Yuzpe regimen of emergency contraception. Fam Plann Perspect. 1996;28(2):58–64, 87.
17. Faculty of Sexual and Reproductive Healthcare Clinical effectiveness Unit. Emergency Contraception. 2011. [Accessed 4/11/2011]. Available from: http://www.fsrh.org/pdfs/CEUguidanceEmergencyContraception11.pdf
18. De Santis M, Cavaliere AF, Straface G, Carducci B, Caruso A. Failure of the emergency contraceptive levonorgestrel and the risk of adverse effects in pregnancy and on fetal development: an observational cohort study. Fertility and sterility. 2005;84(2):296–9.
19. Zhang L, Chen J, Wang Y, Ren F, Yu W, Cheng L. Pregnancy outcome after levonorgestrel-only emergency contraception failure: a prospective cohort study. Hum Reprod. 2009;24(7):1605–11.
20. Cleland K, Raymond E, Trussell J, Cheng L, Zhu H. Ectopic pregnancy and emergency contraceptive pills: a systematic review. Obstet Gynecol. 2010;115(6):1263–6.
21. Wai Ngai S, Fan S, Li S, Cheng L, Ding J, Jing X, et al. A randomized trial to compare 24 h versus 12 h double dose regimen of levonorgestrel for emergency contraception. Hum Reprod. 2005;20(1):307–11.
22. Wilcox AJ, Dunson D, Baird DD. The timing of the “fertile window” in the menstrual cycle: day specific estimates from a prospective study [In Process Citation]. BMJ (Clinical research ed. 2000;321(7271):1259–62.
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24. Faculty of Sexual & Reproductive Healthcare. UK Medical Eligibility Criteria for Contraceptive Use. 2009. [Accessed 4/11/2011]. Available from: http://www.fsrh.org/pdfs/UKMEC2009.pdf
25. von Hertzen H, Piaggio G, Ding J, Chen J, Song S, Bartfai G, et al. Low dose mifepristone and 2 regimens of levonorgestrel for emergency contraception: a WHO multicentre randomised trial. The Lancet. 2002;360(9348):1803–10.
26. Harris M, Bailey L, Bridges-Webb C, Furler J, Joyner B, Litt J, et al. Guidelines for preventive activities in general practice. 6th ed. Mlebourne: RACGP; 2009.
27. Gainer E, Massai R, Lillo S, Reyes V, Forcelledo ML, Caviedes R, et al. Levonorgestrel pharmacokinetics in plasma and milk of lactating women who take 1.5 mg for emergency contraception. Hum Reprod. 2007;22(6):1578–84.
28. Effectiveness and side effects of immediate postcoital levonorgestrel used repeatedly for contraception.United Nations Development Programme/ United Nations Population Fund/World Health Organization/World Bank Special Programme of Research, Development and Research Training in Human Reproduction, Task Force on Post-Ovulatory Methods of Fertility Regulation. vonhertzenh@who.ch. Contraception. 2000;61(5):303–8.
29. Gray RH, Pardthaisong T. In utero exposure to steroid contraceptives and survival during infancy. American journal of epidemiology. 1991;134(8):804–11.
30. Pardthaisong T, Gray RH. In utero exposure to steroid contraceptives and outcome of pregnancy. American journal of epidemiology. 1991;134(8):795–803.
31. Brent RL. Nongenital malformations following exposure to progestational drugs: the last chapter of an erroneous allegation. Birth Defects Res A Clin Mol Teratol. 2005;73(11):906–18.
32. Glasier AF, Cameron ST, Fine PM, Logan SJ, Casale W, Van Horn J, et al. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis. Lancet. 2010.
Notes
a Available as Levonelle®-1, NorLevo®-1, Postinor®-1
b Available as Levonelle®-2, NorLevo®, Postinor®-2
c There is no evidence to indicate the most effective dosing regime when using 30 mcg LNG progestogen only pills for EC. By convention they are taken as 2 doses of 25 tablets 12 hours apart
d Product Information (PI) for LNG-EC states, Only limited data are available in young women of child bearing potential aged 14 to 16 years. No data are available about use in young women aged less than 14 years or in children. Although as with most medications, young women and girls aged less than 16 years have had limited representation in trials, there is no evidence of risk in using LNG-EC in this age group.
e One Thai study showed a lowered birth weight and higher infant mortality in infants whose mothers conceived soon after a DMPA injection.(29, 30)
Disclaimer
Medical knowledge is constantly changing. As new information becomes available, changes in treatment, procedures, equipment and the use of drugs becomes necessary. The contributors and the publishers have as far as possible, taken every care to ensure that the information contained in this text is as accurate as possible at the time of writing. Readers are strongly advised to confirm that the information, especially with regard to drug usage, complies with present legislation and accepted standards of practice. Neither the editors nor the publishers accept any responsibility for difficulties that may arise as a result of any health practitioner acting on the advice and recommendations it contains.