Print Friendly, PDF & Email

Contraceptives (or birth control) are methods for preventing pregnancy by stopping one or more of ovulation, fertilisation and implantation. There are many types of contraceptives, each with their own benefits and limitations. As a doctor, it is important to have an understanding of this to adequately inform your patients about the most suitable contraceptives based on their lifestyle and medical history.



Types

There are several categories of contraceptives:

  • Barrier methods
  • Combined contraceptives
  • Progesterone-only contraceptives
  • Long-acting reversible contraceptives (LARCs)
  • Sterilisation
  • Natural family planning
  • Emergency contraception

Barrier methods

Barrier methods of contraception reduce the risk of pregnancy by acting as a barrier to stop the sperm and ovum meeting and so preventing fertilisation. These should be recommended to patients for all types of sexual contact to reduce sexually transmitted infection (STI) transmission.

 

Male condoms

Male condoms are barriers made of latex, polyisoprene or polyurethane that cover the penis to prevent semen containing sperm from entering the vagina.

 

Benefits:

  • Only used during intercourse
  • Reduces STI transmission
  • Rarely side effects from use

 

Limitations:

  • Can break, split or tear during use
  • Can interrupt intercourse to put a male condom on
  • Need to know the correct technique for using condoms
  • Some patients are allergic to latex condoms

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 18%

 

Female condoms

Female condoms are a barrier made of polyurethane that goes inside the vagina to prevent sperm from passing through the cervix and fertilising an ovum.

 

Benefits:

  • Only used during intercourse
  • Reduces STI transmission
  • Rarely side effects from use

 

Limitations:

  • Can break, split or tear during use
  • May interrupt intercourse to put the female condom in place
  • Need to know the correct technique for using condoms
  • Female condoms are not as widely available as male condoms

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 12%

 

Diaphragm

The diaphragm (or contraceptive cap) is a silicone cup which is placed over the cervix as a barrier to sperm.

 

Benefits:

  • Only used during intercourse
  • Can be put in place in advance of intercourse
  • Rarely side effects from use

 

Limitations:

  • Can break, split or tear during use
  • May interrupt intercourse to put the diaphragm in
  • Patients need to know the correct technique for using a diaphragm
  • Does not protect against STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 12%

 

Barrier methods of contraception

Barrier methods of contraception


Combined contraceptives

Combined contraceptives contain forms of both oestrogen and progesterone. They work by mimicking the luteal phase of the menstrual cycle, leading to inhibition of the hypothalamic-pituitary-gonadal axis. This prevents the release of LH and FSH needed for ovulation.

Combined contraceptives further reduce the risk of pregnancy by thickening the cervical mucus to prevent sperm passage and by thinning the endometrium to reduce the chance of implantation.

 

Medical contraindications

Certain patient groups are contraindicated from using combined contraceptives, including those with:

  • Migraine with aura
  • Current breast cancer
  • High VTE risk factors, such as:
    • Atrial fibrillation
    • SLE positive for antiphospholipid antibodies
    • Age over 35 years old and smoking at least 15 cigarettes daily
    • History of stroke
    • History of VTE
    • Major surgery with prolonged immobilisation
    • Known thrombogenic mutations
    • Complicated valvular or congenital heart disease
  • Other cardiovascular risk factors such as:
    • Hypertension: >160mmHg systolic BP or >100mmHg diastolic BP
    • History of ischaemic heart disease
  • Severe liver disease

The oestrogen in combined contraceptives increases the risk of VTE in patients taking them. Any risk factors for VTE should be considered before the prescription of combined contraceptives.

There is some evidence to suggest that the risk of breast cancer is increased in individuals using combined contraceptives. However, this risk reduces to normal levels 10 years after stopping the contraceptive. Patients with a history of breast cancer may be allowed to use combined contraceptives but this should only be prescribed with the guidance of their oncology team.

 

Combined oral contraceptive pills (COCP)

These are pills containing oestrogen and progesterone that inhibit ovulation. Patients take one pill at the same time each day for 21 days. They then have a 7-day break with either no pills or placebo pills when they have a period-like withdrawal bleed, before starting the next pack of pills. A commonly prescribed example is Microgynon®.

This type of contraception is most suited to women who are good at remembering to take pills daily and who tolerate hormonal contraceptives.

 

Benefits:

  • Does not interrupt intercourse
  • Can be stopped at short notice if not tolerated
  • May make periods more regular, lighter and less painful
  • May reduce the risk of ovarian, endometrial and bowel cancer
  • May have therapeutic benefits in gynaecological disorders including endometriosis and menorrhagia

 

Limitations:

  • Effectiveness reduced if pill is forgotten
  • Side effects may include headaches, nausea, breast tenderness and mood swings
  • Vomiting and diarrhoea may affect effectiveness
  • Certain drugs including some antibiotics and anti-epileptic drugs may affect effectiveness
  • Increases the risk of VTE and stroke
  • Potentially increases the risk of breast cancer while using the COCP
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 9%

 

Contraceptive patches

Contraceptive patches deliver their oestrogen and progesterone through the skin and inhibit ovulation as above. They are approximately 4x4cm in size and can be applied to any skin except the breast, where the tissue is oestrogen sensitive. Common sites to apply them are on the back, abdomen and buttocks. One patch is applied for 7 days and then immediately changed for a new patch. 3 patches should be worn for 21 days in total and then there should be 7 days without a patch when they have a period-like withdrawal bleed. The next 21 days of patches should be started after exactly 7 days.

This type of contraceptive might be well suited to someone who does not mind wearing the patch but tends to forget pills.

 

Benefits:

  • Do not need to remember daily like the pill
  • Does not interrupt intercourse
  • Can be stopped at short notice if not tolerated
  • May make periods more regular, lighter and less painful
  • May reduce the risk of ovarian, endometrial and bowel cancer
  • Vomiting and diarrhoea do not affect effectiveness unlike the pill

 

Limitations:

  • Protection from pregnancy may be affected if they forget to change the patch or if it falls off
  • Side effects may include headaches, nausea, breast tenderness and mood swings
  • Certain drugs may affect effectiveness including some anti-epileptic drugs
  • Increases the risk of VTE and stroke
  • Potentially increases the risk of breast cancer while using the patch
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 9%

 

Vaginal rings

The contraceptive vaginal ring (also known as the NuvaRing®) is a small plastic ring that is placed high in the vagina and secretes oestrogen and progesterone to prevent ovulation. The ring is inserted into the vagina for 21 days and then removed for 7 days before the next ring is put in.

 

Benefits:

  • Do not need to remember daily like the pill
  • Does not interrupt intercourse
  • Can be stopped at short notice if not tolerated
  • May make periods more regular, lighter and less painful
  • May reduce the risk of ovarian, endometrial and bowel cancer
  • Vomiting and diarrhoea do not affect effectiveness unlike the pill

 

Limitations:

  • Side effects may include headaches, nausea, breast tenderness and mood swings
  • Certain drugs may affect protection including some anti-epileptic drugs
  • Increases the risk of VTE and stroke
  • Potentially increases the risk of breast cancer while using the ring
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 9%

Combined contraceptives

Combined contraceptives

Combined contraceptives

Combined contraceptives


Progesterone-only contraceptives

Progesterone only pill (POP)

The progesterone only pill is taken every day without any breaks. It contains only progesterone without any oestrogen. There are a couple of types of POP used currently:

  • Desogestrel POP works mainly by inhibiting ovulation. It also by thickening cervical mucus and thinning the endometrium. This POP should be taken within the same 12 hours every day to be effective. A commonly prescribed example of this type is Cerazette®.
  • Norethisterone and levonorgestrel POPs works mainly by thickening cervical mucus and thinning the endometrium. This POP should be taken within the same 3 hours every day to be effective.

 

Benefits:

  • Suitable for patients where oestrogen is contraindicated or those who are intolerant to oestrogen
  • Taken without breaks so don’t have to remember to start and stop pills
  • Does not interrupt intercourse
  • Can be stopped at short notice if not tolerated

 

Limitations:

  • Protection from pregnancy affected if pill is forgotten
  • May cause irregular bleeding, amenorrhoea or more frequent bleeding
  • Vomiting and diarrhoea may affect protection
  • Certain drugs including some antibiotics may affect effectiveness
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 9%

 

Contraceptive injection

The injection contains progesterone only and is carried out every 12 weeks. It is typically administered intramuscularly into the buttocks. The systemic progesterone inhibits ovulation, thickens the cervical mucus and thins the endometrium. A commonly given type is the Depo-Provera®.

 

Benefits:

  • Suitable for patients where oestrogen is contraindicated or those who are intolerant to oestrogen
  • Do not need to remember to take a pill daily
  • Does not interrupt intercourse

 

Limitations:

  • May cause irregular bleeding, amenorrhoea or more frequent bleeding
  • Patient needs to tolerate injections
  • Effectiveness reduced if late getting next injection
  • Can affect bone mineral density if used long-term
  • Certain drugs including some antibiotics may affect effectiveness
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 6%

Progesterone-only contraceptives

Progesterone-only contraceptives

 


Long Acting Reversible Contraceptives (LARCs)

LARCs are methods of contraception that are inserted into the patient. They are effective for several years before they need replacing. They may be a good choice of contraceptive for women who do not want to become pregnant for a longer period of time.

Implant

The contraceptive implant is a small plastic rod approximately 4cm in length inserted under the skin in the upper arm. It slowly releases progesterone to prevent pregnancy by inhibiting ovulation as well as thickening the cervical mucus and thinning the endometrium. A commonly used type is Nexplanon®.

 

Benefits:

  • Once inserted, it lasts for 3 years
  • Suitable for those who cannot use oestrogen
  • Very effective in preventing pregnancy
  • Does not interrupt intercourse

 

Limitations:

  • May cause irregular bleeding, amenorrhoea or more frequent bleeding
  • Can cause or worsen acne
  • Procedure to fit and remove it which has a risk of bruising and infection
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 0.05%

 

Hormonal coil

Hormonal coils, also known as intrauterine systems (IUS), are T-shaped plastic rods inserted into the uterus that release progesterone locally. They prevent pregnancy by thinning the endometrium to prevent implantation and by thickening cervical mucus to prevent sperm passage.

The Mirena® is a hormonal coil licensed for use for 5 years for contraception and for treating menorrhagia.

The Jaydess® is a slightly smaller coil that is licensed for 3 years. This might be more suitable for women who find the larger Mirena painful to have fitted, such as some nulliparous women.

 

Benefits:

  • It lasts for 3 or 5 years
  • Suitable for those who cannot take oestrogen
  • Very effective in preventing pregnancy
  • Does not interrupt intercourse
  • More likely than the implant to reduce heavy menstruation

 

Limitations:

  • Can make menstruation irregular especially in the first 6 months from fitting and can cause amenorrhoea
  • Can cause acne, headaches and breast tenderness
  • Procedure to fit and remove it which some find too painful to tolerate and has a risk of infection and uterine perforation
  • Can be expelled from the uterus
  • If pregnancy occurs, more likely to be an ectopic pregnancy
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 0.2%

 

Copper coil

Copper coils, also known as intrauterine devices (IUD), are T-shaped plastic and copper rods inserted into the uterus. They prevent pregnancy by creating an inhospitable environment for the sperm and ovum to survive in the uterus.

 

Benefits:

  • It lasts for 10 years
  • Suitable for women who cannot use hormonal contraceptives
  • Very effective in preventing pregnancy
  • Does not interrupt intercourse to use it
  • Effectiveness unaffected by other medications
  • Can be used as emergency contraception

 

Limitations:

  • Can cause heavier, longer and more painful menstruation
  • Procedure to fit and remove it which some find too painful to tolerate and has a risk of infection and uterine perforation
  • Can be expelled from the uterus
  • If pregnancy occurs, more likely to be an ectopic pregnancy
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 0.8%

Long-acting reversible contraceptives (LARCs)

Long-acting reversible contraceptives (LARCs)


Sterilisation 

Female sterilisation

Female sterilisation is a procedure usually done under general anaesthetic or sometimes at the time of Caesarian section. It is considered irreversible when counselling patients, though it is possible in some cases to surgically reverse. Hence, it is only suitable for women who are certain they do not want to become pregnant in the future.

 

There are several methods of female sterilisation:

  • Tubal occlusion with surgical clips
  • Hysteroscopic sterilisation using fallopian implants
  • Salpingectomy

 

Benefits:

  • Permanent contraception
  • Does not interrupt intercourse
  • Does not affect their hormonal levels
  • Effectiveness unaffected by other medications

 

Limitations:

  • Carries risks of surgery including bleeding and infection
  • Many women experience pain after their surgery
  • Very difficult to reverse
  • Women need to be informed that in rare cases they can still become pregnant
  • If pregnancy occurs, more likely to be an ectopic pregnancy
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 0.5%

 

Male sterilisation

Male sterilisation, or vasectomy, involves a procedure under a local anaesthetic to the scrotum and testicles to remove a section of each vas deferens. This prevents pregnancy by stopping the sperm from entering the semen to prevent fertilisation. As vasectomy is considered irreversible, this procedure is only suitable for men who do not intend to have children in the future.

 

Benefits:

  • Permanent contraception
  • Does not interrupt intercourse
  • Less invasive and lower risk procedure than female sterilisation

 

Limitations:

  • Carries risks of surgery including bleeding and infection
  • Some men experience pain after their surgery
  • Very difficult to reverse
  • Contraception should be used afterwards until semen confirmed to be sperm-free
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 0.15%

 


Natural family planning

Natural family planning, or fertility awareness, is where intercourse is timed to coincide with the times during the menstrual cycle when ovulation is least likely. Fertility signs such as body temperature and cervical secretions may be monitored by the individual. This aims to prevent pregnancy by reducing the risk of the ovum being available for fertilisation by the sperm. This method is unsuitable for women with irregular menstrual cycles.

 

Benefits:

  • There are no side effects from this type of contraception
  • It is acceptable to most faiths and cultures

 

Limitations:

  • Much less effective form of contraception
  • Must avoid sex or use other contraception around time of ovulation
  • Needs daily recording of fertility signs
  • Fertility signs are unreliable when breastfeeding
  • Fertility signs can be affected by illness and stress
  • Does not protect from STIs

Percentage of unintended pregnancies within 1 year with typical use of contraception method = 24%

Sterilisation and natural family planning

Sterilisation and natural family planning

 


Emergency contraception

Emergency contraception is used by women who have had unprotected intercourse but do not want to become pregnant. There are three methods of emergency contraception discussed below. Levonelle® and ellaOne® are forms of emergency contraceptive pills or morning-after pills. The copper coil can also be used as emergency contraception. All are more effective the earlier they are used following unprotected intercourse.

 

Levonelle®

This contains a high dose of the synthetic progesterone Levonorgestrel. It is thought to prevent pregnancy by delaying or stopping ovulation. This must be taken within 72 hours of the unprotected intercourse to be effective. It can be taken if the woman has recently used a progesterone-containing contraceptive.

 

ellaOne®

ellaOne, which contains ulipristal acetate, prevents pregnancy by delaying or stopping ovulation. It must be taken within 120 hours to be effective. Its effectiveness is reduced by progesterone so is not suitable for women who have recently used a progesterone-containing contraceptive.

 

Copper coil

The copper coil, or IUD, prevents pregnancy as discussed in the section above. It can be used as emergency contraception if inserted within 120 hours of the unprotected intercourse. It is the most effective method of emergency contraception. It can then be left in place to give long-term contraception if desired.

 


References

1. Your contraception guide – NHS.uk. 2018 [cited 14 February 2018]. Available from: https://www.nhs.uk/conditions/contraception/

2. Effectiveness of family planning methods. Cdc.gov. 2018 [cited 14 February 2018]. Available from: https://www.cdc.gov/reproductivehealth/unintendedpregnancy/pdf/family-planning-methods-2014.pdf

3. Collins S, Arulkumaran S, Hayes K, Jackson S, Impey L. Oxford Handbook of Obstetrics and Gynaecology. 3rd ed. Oxford: Oxford University Press; 2013.

4. FSRH (2012) Combined hormonal contraception.Faculty of Sexual & Reproductive Health

5. FSRH (2016) UK Medical Eligibility Criteria UKMEC 2016.Faculty of Sexual & Reproductive Health This guideline lays out the relative and absolute contraindications to each type of contraception so is really useful.