Contraception

Abstract

The development of new methods of contraception takes a long time. No new methods have become available in the UK in recent years and there are none on the near horizon. Activity in the arena of contraception has recently focussed on the production of guidelines designed to improve contraceptive prescribing among health professionals. New data on the effect on unintended pregnancy and abortion rates of increased access to hormonal emergency contraception has cast doubt on the benefits of EC on public health outcomes. The development of new methods of contraception takes a long time. No new methods have become available in the UK in recent years and there are none on the near horizon. Activity in the arena of contraception has recently focussed on the production of guidelines designed to improve contraceptive prescribing among health professionals. New data on the effect on unintended pregnancy and abortion rates of increased access to hormonal emergency contraception has cast doubt on the benefits of EC on public health outcomes. Most contraceptive users are young, medically fit, and can use any method safely. However, a few medical conditions are associated with theoretical increased health risks with certain contraceptives − particularly hormonal methods − either because the method adversely affects the condition or because the condition, or its treatment, affects the contraceptive. For example, the combined pill may increase the risk of a diabetic woman developing cardiovascular complications and antiretroviral drugs used to treat AIDS may interfere with the efficacy of hormonal contraceptives. Some physiological conditions, such as age and breastfeeding, and behaviours such as heavy smoking, may also affect the theoretical safety of some methods. Since most trials of new contraceptives deliberately exclude subjects with serious medical conditions, heavy smokers, breastfeeding women and women at the extremes of reproductive age, there is very little direct evidence on which to base prescribing advice. In an attempt to produce a set of international norms for providing contraception safely to women and men with a range of conditions which may contraindicate one or more methods, the World Health Organization (WHO) developed a system addressing medical eligibility criteria (MEC) for contraceptive use.1World Health Organization Medical eligibility for contraceptive use.3rd edn. WHO, Geneva2004Google Scholar The WHOMEC (which are updated regularly) are intended for use by policy makers and programme managers. Recognizing that national health policies, needs and resources vary considerably around the world, WHO expected national organisations to adapt the guidelines for use in their own country. During 2005/06, the Faculty of Family Planning and Reproductive Healthcare (FFPRHC) undertook a formal consensus process designed to adapt the WHOMEC for use in the UK.2Faculty of Family Planning and Reproductive Healthcare. UK medical eligibility criteria for contraceptive use (UKMEC 2005/2006). Available at: http://www.ffprhc.org.uk/admin/uploads/298_UKMEC_200506.pdf [Accessed 2 April 2007].Google Scholar In late 2006, a hard copy of the UK Medical Eligibilty Criteria (an A4-sized reference book, together with laminated copies of the summary tables for day-to-day use in clinics) was sent to every general practice, family planning and genito-urinary medicine clinic in the UK. The guidance UKMEC is also available on the FFPRHC website.2Faculty of Family Planning and Reproductive Healthcare. UK medical eligibility criteria for contraceptive use (UKMEC 2005/2006). Available at: http://www.ffprhc.org.uk/admin/uploads/298_UKMEC_200506.pdf [Accessed 2 April 2007].Google Scholar Using evidence-based systematic reviews and expert opinion, conditions are classified into one of four categories (Table 1). Category 1 includes conditions for which there is no restriction for the use of the method, while category 4 includes conditions which represent an unacceptable health risk if the contraceptive is used (absolutely contraindicated). Classification of a condition as category 2 indicates that the method may generally be used but that more careful follow-up is required. Category 3 conditions are those for which risks of the contraceptive generally outweigh the benefits (relatively contraindicated). Provision of a method to women with category 3 conditions requires careful clinical judgement since use is not recommended unless there is no acceptable alternative. In these circumstances, the provider should seek advice from an expert. For some conditions, the MEC distinguish between a method being started for the first time (initiation) and its continuation. If, for example, a women develops for the first time migraine with aura while she is using, say, Depo Provera® (Pharmacia), continuation of Depo Provera® falls into category 3 (the theoretical risks outweigh the benefits). If a woman who already has migraine with aura wants to start using Depo Provera®, the condition is regarded as category 2 − the benefits of using the method outweigh the theoretical risks (Table 2).UK Medical Eligibilty Criteria classification categories1A condition for which there is no restriction for the use of the contraceptive method2A condition where the advantages of using the method generally outweigh the theoretical or proven risks3A condition where the theoretical or proven risks usually outweigh the advantages of using the method4A condition which represents an unacceptable health risk if the contraceptive method is used.Table 2UK Medical Eligibility Criteria – prescribing progestogen-only contraceptives to women with common neurological conditionsConditionCategoryClarifications/evidencePOPDMPAIMPNeurological conditionsICICICHeadachesa) non-migrainous (mild or severe)111111Classification depends on accurate diagnosis of those severe headaches that are migrainous and those that are not. Non-migrainous headaches include tension-type, cluster or rebound headachesb) Migrainei) without aura, age < 35 years122222ii) without aura, age ≥ 35 years122222Aura (focal symptoms) indicates ischaemia: homonymous hemianopia, unilateral paraesthesia and/or numbness, unilateral weakness; and aphasia or unclassifiable speech disorder. Visual symptoms progress from fortification spectra (a star-shaped figure near the point of fixation with scintillating edges) to scotoma (a bright shape which gradually increases in size). Flashing lights are not focal symptoms. Aura occurs before the onset of headacheiii) with aura, at any age232323c) Past history of migraine with aura, at any age222Any new headaches or marked changes in headaches should be evaluated. Classification is for women without any other risk factors for stroke. Risk of stroke increases with age, hypertension, and smokingEpilepsy111If a woman is taking liver enzyme inducing anticonvulsants, refer to the section on drug interactions. Certain anticonvulsants lower the efficacy of POP and implantDepressive disordersDepression111The classification is based on data for women with selected depressive disorders. No data on bipolar disorder or postpartum depression were available. There is a potential for drug interaction between certain antidepressant medications and hormonal contraceptives.Evidence: POPs did not increase depressive symptoms in women with depression compared to baseline.I, initiation; C, continuation; POP, progestogen-only pill; DMPA, depot medroxyprogesterone acetate; NET-EN, noretisterone ethanate; IMP, implanon. Open table in a new tab 1A condition for which there is no restriction for the use of the contraceptive method2A condition where the advantages of using the method generally outweigh the theoretical or proven risks3A condition where the theoretical or proven risks usually outweigh the advantages of using the method4A condition which represents an unacceptable health risk if the contraceptive method is used. I, initiation; C, continuation; POP, progestogen-only pill; DMPA, depot medroxyprogesterone acetate; NET-EN, noretisterone ethanate; IMP, implanon. In October 2005 the National Institute for Health and Clinical Excellence (NICE) published a guideline on long-acting reverisble methods of contraception (LARC).3National Institute for Health and Clinical Excellence Long-acting reversible contraception. NICE, LondonOctober 2005www.nice.org.ukGoogle Scholar While modern methods of contraception are effective at preventing pregnancy if they are used perfectly, methods which rely on consistent and correct use are associated with higher failure rates when they are used typically. Long-acting methods, which do not require the user to take action any more frequently than every four weeks, include intra-uterine devices and systems (which last at least 5 years), contraceptive implants (which last at least three years), progestogen only injectables (Depo Provera® lasting 12 weeks and norethisterone enanathate lasting 8 weeks) as well as the combined contraceptive vaginal ring, which provides contraceptive protection for four weeks but which is not licensed in the UK. There is good evidence that the use of LARC is associated with a lower risk of unintended pregnancy.4Darney P.D. Callegari L.S. Swift A. Atkinson E.S. Robert A.M. Condom practices of urban teens using Norplant contraceptive implants, oral contraceptives and condoms for contraception.Am J Obstet Gynecol. 1998; 180: 929-937Abstract Full Text Full Text PDF Scopus (54) Google Scholar, 5Santelli J.S. Lindberg L.D. Finer L.B. Singh S. Explaining recent declines in adolescent pregnancy in the United States: the contribution of abstinence and improved contraceptive use.Am J Public Health. 2007; 97: 1-7Google Scholar The uptake of LARC is low in Britain; only 10% of women aged 16 to 49 were using any LARC in 2005/06, compared with 23% of women using the oral contraceptive pill and 21% the condom.6Taylor T. Keyse L. Bryant A. Contraception and sexual health 2005/06. Office for National Statistics, London2006Google Scholar Recognizing both the potential of LARC to reduce unintended pregnancy rates and the low use, NICE developed a detailed guideline giving evidence-based recommendations about all LARC methods available in the UK. The guideline is lengthy; arguably the most important recommendations relate to those which promote the use of LARC and draw attention to the cost effectiveness of all LARC methods compared with oral contraception and condoms (Table 3).Recommendations from the NICE guideline on long-acting reversible contraception1Women requiring contraception should be given information about and offered a choice of all methods, including long-acting reversible contraception (LARC) methods.2Women should be provided with the method of contraception that is most acceptable to them provided it is not contraindicated.3Contraceptive service providers should be aware that:•all currently available LARC methods (intrauterine devices [IUDs], the intrauterine system [IUS], injectable contraceptives and implants) are more cost effective than the combined oral contraceptive pill even at 1 year of use•IUDs, the IUS and implants are more cost effective than the injectable contraceptives•increasing the uptake of LARC methods will reduce the number of unintended pregnancies 1Women requiring contraception should be given information about and offered a choice of all methods, including long-acting reversible contraception (LARC) methods.2Women should be provided with the method of contraception that is most acceptable to them provided it is not contraindicated.3Contraceptive service providers should be aware that:•all currently available LARC methods (intrauterine devices [IUDs], the intrauterine system [IUS], injectable contraceptives and implants) are more cost effective than the combined oral contraceptive pill even at 1 year of use•IUDs, the IUS and implants are more cost effective than the injectable contraceptives•increasing the uptake of LARC methods will reduce the number of unintended pregnancies Many people are still confused about the advice that the Medicine and Healthcare Products Regulatory Agency (MHRA) issued in November 2004 about the use of Depo Provera®.7Updated prescribing advice on the effect of Depo-Provera contraception on bones. Available at: http://www.mhra.gov.uk/home/idcplg?IdcService=SS_GET_PAGE&nodeId=238 [Accessed 2 April 2007].Google Scholar In response to a growing body of evidence that use of Depo Provera® is associated with a reduction in bone mineral density (BMD), the MHRA advised that: •in adolescents Depo Provera® may be used as a first-line contraceptive, but only after other methods have been discussed with the patient and considered to be unsuitable or unacceptable•the committee also recommended careful re-evaluation of the risks and benefits of treatment in women of all ages who wish to continue use of Depo Provera® for more than two years•finally, the committee on safety of medicines (CSM) advised that women who had significant lifestyle or medical risk factors for osteoporosis should consider other methods of contraception.Some people are interpreting this advice to mean that young people cannot use Depo Provera®, and that for all women, use should be restricted to 2 years. A meeting of experts at WHO, held in 2005, reviewed all of the evidence on the effect of Depo Provera® on BMD.8World Health Organization Technical consultation on the effect of hormonal contraception on bone health. WHO, 2006http://www.who.int/reproductivehealth/family_planning/docs/hc_bonehealth/consultation_rpt.pdfDate: 2006Google Scholar The conclusions of the meeting are shown in Table 4.Conclusions of the World Health Organization technical consultation on the effect of hormonal contraception on bone health•Depo Provera® use reduces BMD in women who have attained peak bone mass (PBM) and impairs the acquisition of bone mineral among those who have not yet attained PBM•The loss of BMD is small - 5 to 7% of BMD in the hip and the spine is lost after two years. The rate of loss subsequently appears to decrease over time•When Depo Provera® is discontinued, BMD is restored to within the normal range unless women have reached menopause when they may not have time to regain BMD•It is not clear whether the loss in BMD among adolescents prevents attainment of potential peak bone mass•Insufficient data exists to assess whether Depo Provera® use modifies the absolute risk of fracture in the reproductive years or in postmenopausal life•Since the effect on bone mineral density is largely reversible, any lifetime increase in fracture risk is likely to be small •Depo Provera® use reduces BMD in women who have attained peak bone mass (PBM) and impairs the acquisition of bone mineral among those who have not yet attained PBM•The loss of BMD is small - 5 to 7% of BMD in the hip and the spine is lost after two years. The rate of loss subsequently appears to decrease over time•When Depo Provera® is discontinued, BMD is restored to within the normal range unless women have reached menopause when they may not have time to regain BMD•It is not clear whether the loss in BMD among adolescents prevents attainment of potential peak bone mass•Insufficient data exists to assess whether Depo Provera® use modifies the absolute risk of fracture in the reproductive years or in postmenopausal life•Since the effect on bone mineral density is largely reversible, any lifetime increase in fracture risk is likely to be small So what should we be advising to women who want to use or who are using Depo Provera®? There should be no restriction on longterm use of Depo Provera® among women aged 18 to 45 who are otherwise eligible to use it. They should be reviewed every two years and reminded about loss of BMD. Unless new significant risk factors for osteoporosis (e.g. use of steroids, BMI <18) have arisen, they can continue Depo Provera® if they wish to. Neither BMD nor serum estradiol concentrations need be measured. Among people under the age of 18 years, the advantages of using Depo Provera® generally outweigh the theoretical safety concerns regarding fracture risk. As the CSM recommends, Depo Provera® can be used if other methods have been discussed and rejected. Adolescents too should be reviewed after 2 years but there is no absolute limit on the duration of the use by teenagers. Remember, teenage pregnancy also leads to loss of bone. Among women over the age of 45 years, the advantages of starting Depo Provera® for the first time for contraception are generally outweighed by the theoretical concerns about fracture risk since the risk of pregnancy is diminishing at that age. For women who are already using Depo Provera®, the risks of continuation should be discussed, but if the woman wishes to continue she should generally be allowed to do so. Emergency contraception (EC) was made available as a pharmacy-only medicine in 2001. This action has not increased overall use of EC, but has reduced the number of women who go to their GP to get it.9Marston C. Meltzer H. Majeed A. Impact on contraceptive practice of making emergency hormonal contraception available over the counter in Great Britain:repeated cross sectional surveys.BMJ. 2005; 331: 271-275Crossref PubMed Scopus (117) Google Scholar Most women who have an unintended pregnancy still do not use emergency contraception. In 2005/06, 5% of women of reproductive age and 15% of women aged 16−17 said they had used EC in the last year. 6Taylor T. Keyse L. Bryant A. Contraception and sexual health 2005/06. Office for National Statistics, London2006Google Scholar Around 10 to 12% of women presenting for abortion claim to have used EC to try to prevent that pregnancy.10Glasier A. Emergency contraception – is it worth all the fuss?.BMJ. 2006; 333: 560-561Crossref PubMed Scopus (19) Google Scholar, 11Lakha F. Glasier A. Unintended pregnancy and use of emergency contraception among a large cohort of women attending for antenatal care or abortion in Scotland.Lancet. 2006; 368: 1782-1787Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar However, among women attending for antenatal care, less than 2% use it to try to prevent pregnancy despite 10% saying the pregnancy was unintended and 25% being somewhat ambivalent about their desire to be pregnant.11Lakha F. Glasier A. Unintended pregnancy and use of emergency contraception among a large cohort of women attending for antenatal care or abortion in Scotland.Lancet. 2006; 368: 1782-1787Abstract Full Text Full Text PDF PubMed Scopus (126) Google Scholar To be effective EC, must be used within 72 hours of intercourse and it is probably most effective when it is taken with 24 hours of sex. It can be difficult to get EC within this time frame and it is expensive (£25) when purchased from a pharmacy. A number of studies have been undertaken in which women have been given a supply of EC to keep at home – thus removing all the barriers to access.10Glasier A. Emergency contraception – is it worth all the fuss?.BMJ. 2006; 333: 560-561Crossref PubMed Scopus (19) Google Scholar All of the studies demonstrate a two- to three-fold increase in the use of EC. Six of them looked at pregnancy or abortion rates as an end point.12Glasier A. Baird D.T. The effects of Self-Administering Emergency Contraception.N Engl J Med. 1998; 339: 1-4Crossref PubMed Scopus (294) Google Scholar, 13Glasier A. Fairhurst K. Wyke S, et al.Advanced provision of emergency contraception has not reduced abortion rates in Lothian.Contraception. 2004; 69: 361-366Abstract Full Text Full Text PDF PubMed Scopus (134) Google Scholar, 14Hu X. Cheng L. Hua X. Glasier A. Advanced provision of emergency contraception to postnatal women in China makes no difference to abortion rates. A randomised controlled trial.Contraception. 2005; 72: 111-116Abstract Full Text Full Text PDF PubMed Scopus (56) Google Scholar, 15Lo S.S.T. Fan S.Y.S. Ho P.C. Glasier A.F. Effect of advanced provision of emergency contraception on women's contraceptive behaviour: a randomized controlled trial.Hum Rep. 2004; 19: 2404-2410Crossref PubMed Scopus (83) Google Scholar, 16Raine T.R. Harper C.C. Rocca C.H. et al.Direct access to emergency contraception through pharmacies and effect on unintended pregnancy and STIs. A randomized controlled trial.JAMA. 2005; 293: 54-62Crossref PubMed Scopus (265) Google Scholar, 17Raymond E.G. Stewart F. Weaver M. Monteith C. Van Der Pol B. Impact of increased access to emergency contraceptive pills: a randomised controlled trial.Obstet Gynecol. 2006; 108: 1098-1106Crossref PubMed Scopus (83) Google Scholar None showed any effect on the number of pregnancies or the abortion rate when women who had a supply of EC to keep at home (and were much more likely to use it) were compared with women who had to go to a doctor or pharmacy to get EC. Even though advanced provision did result in increased use, still at least 3 out of 4 women who had EC at home did not use it when they put themselves at risk of pregnancy. When women were asked why they did not use EC, in the majority of cases it was because they did not recognize (or acknowledge) that they had put themselves at risk of pregnancy. If randomized trials have shown no effect on pregnancy or abortion rates, this does not mean that it is not worth promoting (or using) emergency contraception. As a public health strategy to reduce unintended pregnancy and abortion rates, the potential of EC has almost certainly been overestimated. As long as only one in ten women use it when they have put themselves at risk of pregnancy it is not going to make a measurable difference to abortion rates. However, for an individual woman who has put herself at risk of pregnancy (having had an accident with contraception or unprotected sex) EC is considerably better than nothing. So, women who have unprotected sex or who have had an accident with their chosen method of contraception should be encouraged to use EC, and we should continue to make it easily available. However, women need to understand that EC is much less effective than other contraceptive methods, and if they really want to prevent pregnancy they should be using a contraceptive method during sex or preferably before it.