Contraception - general overview

It could be argued that family planning is a pressing global concern:

  • In the UK, population was officially projected to rise from 60.2 million (mid-2005) to 82.3 million in 2071 - almost another three Londons in less than a lifetime.1
  • The United Nations predicts that world population will rise from today's 6.6 billion to 9.2 billion by 2050. This represents a growth rate of 78 million a year - a population almost the size of Germany's.

Whilst considering and respecting different religious and cultural values, we should strive to ensure that every woman, who wishes to, has access to safe and effective contraception.

Current contraceptive usage in the UK

75% of women aged 16-49 years use some type of contraception:2

  • 25% of women use the combined oral contraceptive pill (COCP).
  • 25% of women rely on male condom use.
  • In women aged 18-29 years, similar numbers of women use the COCP as they do condoms (the most frequent methods).
  • Approximately one third of women under 18 years of age use contraceptives - half using condoms and half taking the COCP.
  • A woman or partner has been sterilised in 17% of reported use.
  • Sterilisation is used more frequently in women aged over 30 years.

Failure rates

Two types of contraceptive failure:

  • User failure: when the contraceptive method not being used properly.
  • Method failure: pregnancy results even though the contraceptive method was used properly.

User failure rates are much higher than method failure rates, especially in first year of use.

Method of contraceptionFirst year failure rates per 100 women.
Range in world literature
Male sterilisation0-0.05
Subcutaneous implant (Implanon®)0-0.07
Female sterilisation0-0.5
Intrauterine system (IUS)0-0.6
Combined oral contraceptive pill (COCP)0.1-3
Intrauterine contraceptive device (IUCD)0.3-0.8 (gold standard devices)
Injectable progestogens0-1
Progestogen-only contraceptive pill (POCP)0.3-4
Evra® contraceptive patch0.6-0.9
No method at age over 50 years0-5.0
Male condom2-15
Coitus interruptus6-17
Fertility awareness2-25
No method at age 45 years or over10-20
No method at age 40 years or over40-50
No method at age under 40 years80-90

Compare options for contraceptive choices. A Brief Decision Aid.

Reversible contraceptive methods are shown below. Sterilisation for men and women, although technically reversible, should be viewed as permanent. They are covered in the separate article Sterilisation (Female Sterilisation and Vasectomy).

Combined oral contraceptive pill

The combined oral contraceptive pill (COCP) is a highly effective form of contraception and used by 25% of women aged 16 to 49 years in the UK to control fertility.2

The COCP contains a combination of synthetic oestrogen and progestogen. They have been classified into first-, second- and third-generation preparations reflecting their hormonal content and period of development. All current brands contain 20-40 micrograms of oestrogen. It is also available as a transdermal (patch) Evra®, and a contraceptive vaginal ring NuvaRing®.4 Both have approximately similar efficacy to the COCP.5

Mode of action

The COCP prevents conception by acting on:6

  • The hypothalamic-pituitary-ovarian axis, to suppress synthesis and secretion of FSH and the mid-cycle surge of LH, thus inhibiting the development of ovarian follicles and ovulation.
  • Cervical mucus to prevent penetration of sperm.
  • The endometrium to inhibit blastocyst implantation.

It works by preventing ovulation, thickening cervical mucus and reducing endometrial receptivity.


  • Highly effective, easy to reverse and convenient to use.
  • Can bring relief from menstrual problems.
  • May protect against pelvic inflammatory disease (PID).
  • Reduces incidence of benign breast disease, ovarian cysts, ovarian cancer and endometrial cancer.


  • Side-effects, e.g. breakthrough bleeding, breast tenderness, mood swings.
  • Increased risk of venous thromboembolism; increased when comparing to non-users, but much less than pregnancy.6
  • Increased risk of myocardial infarction (MI); increased risk is most pronounced in women with risk factors, e.g. smoking, hypertension, diabetes.
  • Increased risk of stroke; twice that of non-users overall, but higher in women with hypertension and smokers.
  • Slightly increased risk of breast cancer; as the incidence of breast cancer under age 40 years is low, absolute risk in young women is small.
  • Increased risk of cervical cancer; but this may be related to other factors, e.g. the number of sexual partners, non-barrier use during intercourse, human papillomavirus (HPV) exposure.
  • Increased risk of primary liver cancer; only with high-dose oestrogen and the absolute risk is very small
  • Increased overall mortality despite careful selection and follow-up.

Progestogen-only contraceptive pill

Approximately 5% of women aged 16-49 years in the UK use the progestogen-only contraceptive pill (POCP).7 It is particularly used when combined hormonal contraception is contra-indicated, e.g. breast-feeding mothers.

Mode of action

  • Ovulation is inhibited in about 60% of cycles (although it does not occur in 100% of cycles normally).8 With desogestrel, ovulation is inhibited in 97% of cycles.
  • Transport of the ovum is delayed.9
  • The cervical mucus becomes more viscous and impenetrable to sperm.
  • The endometrium becomes unsuitable for implantation.


  • It is reliable if taken correctly, is easily reversible and convenient to use.
  • Avoids the cardiovascular risks of oestrogen.
  • It can often be used by women with contra-indications to the COCP.
  • It can be used during breast-feeding.


  • Menstrual problems such as amenorrhoea and breakthrough bleeding.
  • It has to be taken meticulously at the same time each day. The error for forgotten pills is just three hours late for POCPs, with the exception of Cerazette®, which has a licence for 12 hours.
  • There is increased risk of functional ovarian cysts (30% increased risk) and the possibility of breast cancer (similar to the COCP).
  • It is typically used for women who do not tolerate COCPs or for whom they are contra-indicated.

Levonelle® is progestogen-only emergency contraception.

Progestogen injectables

A progestogen-only injectable contraceptive (POIC) is a long-acting, reversible contraceptive. A synthetic progesterone or progestogen is slowly released into the systemic circulation following intramuscular injection. 3% of women aged 16-49 use the injection as their method of contraception.2 This percentage has been stable for some time.

There are two forms of depot injection currently available on the UK market:

  • Depo-Provera® is depot medroxyprogesterone acetate (DMPA) aqueous suspension 150 mg in 1 ml.10 This is most commonly used.
  • Noristerat® is norethisterone enantate (oenanthate) 200 mg in 1 ml in an oily liquid.11 This is only licensed for short-term use, e.g. for women whose partners have undergone vasectomy, until the vasectomy is effective.

Mode of action

  • Its main mechanism of action is to suppress ovulation.
  • It also makes the endometrium unsuitable for implantation if fertilisation occurs.
  • It also increases the viscosity of cervical mucus, making the mucus less easily penetrable to sperm.


  • Very effective and convenient. Provided that the Depo-Provera® is given on a regular basis every 12 weeks (8 weeks for Noristerat®), there is a very low failure rate - fewer than 4 per 1,000 women over two years.12
  • Can be used during breast-feeding.


  • Is not quickly reversible.
  • Menstrual irregularities are found in 80% of women using this method.12
  • Weight gain of up to 3 kg in one year may occur.12
  • Delayed return of fertility; median delay to conception has been reported as 5.5 months plus the estimated duration of the effect of the last injection of Depo-Provera®. This is compared to 3 months for oral contraceptives and 4.5 months after discontinuing the intrauterine contraceptive device (IUCD).13
  • Possible risk of depression; not clearly shown yet.
  • Possible increased risk of breast cancer; not clearly shown yet.
  • Reduction in bone mineral density which is small and recovered as soon as the injections are stopped.14

Progestogen-only subdermal implant

The progestogen-only subdermal implant (POSDI) is a long-acting reversible contraceptive. Etonogestrel contained in a rod is released slowly into the systemic circulation following subdermal insertion in the upper arm.

Nexplanon® is now the only contraceptive implant on the UK market.15 It is a 4 cm flexible rod containing 68 mg etonogestrel (a progestogen). Nexplanon® must be removed after three years when it can then be replaced.

2% of women between the ages of 16 and 49 years use the implant.2

Mode of action

The main mechanism of action of Nexplanon® is to inhibit ovulation. It also thickens the cervical mucus, inhibiting the passage of sperm to the uterus, as well as thinning the endometrium, preventing implantation were an egg to be fertilised.3


  • Highly effective with very few pregnancies reported. The National Institute for Health and Clinical Excellence (NICE) quotes a failure rate of less than 1 in 1,000 women in three years' use.13 The main reason for 'failure' is incorrect timing of insertion, conception prior to insertion and failure of insertion.
  • Long duration of action.
  • Reversible. There is no evidence of delay in return to fertility on removal of Nexplanon®.
  • Very convenient.


  • Irregular bleeding; common in the first year but declines thereafter.
  • Weight gain; 20% of women show 10% increase and this is a common reason for discontinuation, along with headache and acne.16

Intrauterine contraceptive device

The IUCD is a safe and effective method of contraception. Although use in the UK has increased in recent years, only 6% of contraceptive users aged 16-49 years currently use an IUCD.2 There are 150 million users of the IUCD worldwide. The majority are in China. They are ideal for a woman in her forties, with children. Evidence suggests that the latest banded Cu-IUCDs are better than the COCP and as effective as reversible sterilisation.17,18

The gold standard IUCD is the banded T-safe copper 380A. All should only be fitted by properly trained personnel who are fitting IUCDs regularly, i.e. >12/year.

IUCDs have a monofilament thread to permit checking of presence and to allow removal.

Mode of action

They work predominantly by inducing an inflammatory response in the uterus, which affects the viability of sperm and ova. They prevent fertilisation and implantation. They have a duration of action of 5-10 years if they contain 380 mm copper, or until contraception is no longer required in later years of reproductive life.


  • Highly effective, reversible and convenient. Fewer than 2 women in 100 will become pregnant with five years of use of this method.19
  • Effective directly following fitting.


  • Spotting and bleeding between periods. Many patients request removal within 5 years.
  • Increased blood loss and more painful periods especially during the first few cycles.
  • Displacement or expulsion: 1 in 20 women, usually during menses in the first three months and may go unnoticed.19
  • Increased risk of pelvic inflammatory disease (PID): this is in in the first 20 days only and women should be screened before insertion.
  • Uterine perforation: 1/1000 insertions.
  • Ectopic pregnancy: the risk is 1 in 20 if pregnant with an IUCD in situ, so the absolute risk is very low.

Levonorgestrel-releasing intrauterine system

The levonorgestrel-releasing intrauterine system (LNG-IUS) has been licensed as a contraceptive in the UK since May 1995. The LNG-IUS now also has a licence for the management of idiopathic menorrhagia and may therefore be used by women who do not require contraception.

Only one system is available (Mirena®) - a T-shaped device. It can be effective for five years or until contraception is no longer required. The LNG-IUS is used by only 2% of women aged 16-49 years who are currently using a method of contraception.2

Mode of action

This is mainly by reducing endometrial growth and preventing implantation.


  • It is very effective, convenient and reversible. Less than 1 woman in 100 will become pregnant at five years use of this method.19
  • It reduces blood loss and dysmenorrhoea.
  • It may reduce the risk of pelvic inflammatory disease (PID) compared with normal IUCDs, because of thickening of cervical mucus.
  • It does not significantly interact with other drugs, as its action is principally local.


  • Menstrual irregularities are common in the first six months. By 12 months, amenorrhoea or light bleeding is common. 60% of patients request removal within five years.
  • There are typical progestogenic side-effects.
  • Dysfunctional ovarian cyst, but usually resolving spontaneously.
  • There is need for fitting: as larger than normal IUCDs, may require cervical dilatation with local anaesthesia.

Diaphragms and caps

Diaphragms and caps are female barrier methods of contraception. Their popularity as forms of contraception have declined with the availability of more effective methods and with awareness of the need to protect against sexually transmitted infections.20

Diaphragms are thin, dome-shaped devices made of latex or silicone and range in size between 55 mm and 100 mm. Diaphragms should lie diagonally between the posterior fornix and behind the pubic bone. Caps are smaller than diaphragms, fitting closely over the cervix. Both should be used with spermicides. They come in three styles:

  • Flat spring: for women with normal vaginal muscular strength.
  • Arcing spring: for women with poor vaginal muscular strength.
  • Coil spring: may cause less discomfort in some women.

Mode of action

Caps and diaphragms form a physical barrier, preventing entrance of sperm to the cervix.


  • Insertion before intercourse can allow spontaneity.
  • May offer some protection against cervical carcinoma, sexually transmitted diseases and pelvic inflammatory disease (PID).


  • Women needs to be well-motivated and careful in its use.
  • Spermicides can cause local reaction.
  • Urinary tract infection incidence is increased with diaphragms.

Female condoms

The female condom (Femidom®) has been available in Great Britain since 1992. It is made of soft pliable polyurethane, pre-lubricated and has two flexible rings.

Mode of action

This is a barrier method.


  • There are no known side-effects.
  • Helps to prevent sexually transmitted disease and possibly reduces risk of cervical carcinoma.
  • Can be inserted prior to intercourse.


  • Needs careful insertion.
  • Can be pushed into the vagina or bypassed.
  • May be uncomfortable.

Male condoms

The only contra-indication to the use of latex condoms is for people with sensitivity or allergy to latex proteins, as risks generally outweigh benefits.21 Men and women with sensitivity to latex may use male or female polyurethane condoms or deproteinised latex male condoms.

Mode of action

This is a barrier method.


  • Ready availability.
  • Protects against sexually transmitted disease and may protect woman against cervical cancer.


  • They are relatively expensive if purchased (free condom uptake at family planning clinics is low).
  • There is the need for prior planning.
  • Lacks spontaneity.
  • Requires co-operation of both partners.
  • May reduce sensitivity.
  • Can break or slip off, although research shows failures due to breakage or slippage decrease with increasing experience of use.

Natural family planning

Several methods are available, including calendar, temperature, observation of cervical mucus, and palpating the cervix.22


  • There are no side-effects.
  • It complies with religious practices of some patients.


  • Considerable commitment from both partners is required.
  • Unreliable with unpredictable cycles.

Contraception and special groups

Several groups of women have special requirements (see separate article Contraception and Special Groups) regarding contraception; they include:

See also separate articles:

Document references

  1. UK population numbers and world population trend, Optimum Population Trust (2009)
  2. Contraception and Sexual Health 2008/09, Office for National Statistics (2009)
  3. John Guillebaud. Your Questions Answered: Contraception, 4th Edition
  4. Summary of Product Characteristics (SPC) - NuvaRing®; Summary of Product Characteristics (SPC) - NuvaRing®. Vaginal ring with 11.7 mg etonogestrel and 2.7 mg ethinylestradiol for topical vaginal use. Merck, Sharpe and Dohme Limited, electronic medicines compendium. Last updated Aug 2010.
  5. Lopez LM, Grimes DA, Gallo MF, et al; Skin patch and vaginal ring versus combined oral contraceptives for Cochrane Database Syst Rev. 2008 Jan 23;(1):CD003552. [abstract]
  6. First Prescription of Combined Oral Contraception, Faculty of Family Planning and Reproductive Health Care (2007)
  7. No authors listed; Is Cerazette the minipill of choice? Drug Ther Bull. 2003 Sep;41(9):68-9. [abstract]
  8. Milsom I, Korver T; Ovulation incidence with oral contraceptives: a literature review. J Fam Plann Reprod Health Care. 2008 Oct;34(4):237-46. [abstract]
  9. Contraception - progestogen-only methods, Prodigy (Sept 2007)
  10. Summary of Product Characteristics (SPC) - Depo-Provera® 150 mg/ml injection (medroxyprogesterone acetate), Pharmacia Limited, electronic Medicines Compendium. Updated August 2010
  11. Summary of Product Characteristics (SPC) - Noristerat® (norethisterone enantate), Bayer Schering, electronic Medicines Compendium. Updated June 2009
  12. Progestogen-only Injectable Contraception, Faculty of Sexual and Reproductive Healthcare (2009)
  13. Long-acting reversible contraception, NICE Clinical guideline (October 2005); (the effective and appropriate use of long-acting reversible contraception)
  14. Kaunitz AM, Miller PD, Rice VM, et al; Bone mineral density in women aged 25-35 years receiving depot medroxyprogesterone acetate: recovery following discontinuation. Contraception. 2006 Aug;74(2):90-9. Epub 2006 May 19. [abstract]
  15. Summary of Product Characteristics (SPC) - Nexplanon® 68 mg implant for subdermal use, Merck Sharp & Dohme Limited, electronic Medicines Compendium. Updated October 2010
  16. Glasier A; Implantable contraceptives for women: effectiveness, discontinuation rates, return of fertility, and outcome of pregnancies. Contraception. 2002 Jan;65(1):29-37. [abstract]
  17. Sivin I, Shaaban M, Odlind V, et al; A randomized trial of the Gyne T 380 and Gyne T 380 Slimline Intrauterine Copper devices. Contraception. 1990 Oct;42(4):379-89. [abstract]
  18. Andersson K, Odlind V, Rybo G; Levonorgestrel-releasing and copper-releasing (Nova T) IUDs during five years of use: a randomized comparative trial. Contraception. 1994 Jan;49(1):56-72. [abstract]
  19. Intrauterine Contraception, Faculty of Sexual and Reproductive Healthcare (2007)
  20. Contraception - barrier methods and spermicides, Prodigy (Sept 2007)
  21. Male and Female Condoms, Faculty of Family Planning and Reproductive Health Care (2007)
  22. Contraception - natural family planning, Prodigy (Sept 2007)

Internet and further reading

The clinicians responsible for the production of this document are:

Original Author: Dr Hayley Willacy
Last Checked: 7 Oct 2011
Current Version: Dr Hayley Willacy
Document ID: 2004  Version: 26
Peer Reviewer: Dr Hannah Gronow