Women's Health Series: Contraception

Dr. Nick's Women's Health Series continues with a look at contraception: the options and their advantages and disadvantages. We'll let Nick take it from here...

Well, I’m sure most of you know what contraception is, but I’m always surprised at how many women will walk into my practice and ask for a repeat of their oral contraceptive, not aware of all the other options available to them, especially the long-acting reversible contraceptives.

How effective a contraceptive is, depends on two factors: firstly, the type of contraceptive and secondly, it’s correct use. For example, without the use of a contraceptive, 85 in 100 women will become pregnant within one year of being sexually active. The combined pill on the other hand is more than 99% effective if…and here’s the catch, IF used correctly. If for example you forget to take a pill, the effectiveness drops, in some cases and with some pills by a lot.

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Barrier Methods

Caps & Diaphragms

Both these methods consist of a silicone or latex domes that are inserted into the vagina before sex. In doing so they cover the uterus and prevent any sperm entering the womb. They should both be used with spermicide (a gel/cream that kills sperm) and be left in place for at least six hours after sex. They come in various shapes and sizes and so need to be initially fitted by a nurse or specialist.

If used correctly, they are about 92-96% effective at preventing pregnancy.


  • You can put it in at a convenient time before sex
  • As it contains no hormones, there is no serious associated health risks or side effects


  • Not as effective as other forms of contraception
  • Very limited protection against STIs
  • Can be a bit of a “mood changer” as it can interrupt sex
  • Some women and their sexual partners may have allergies to the latex and spermicide
  • May cause bladder infections in some women
  • Takes some practice to get used to it


Male condoms - worn on the penis

Female condoms - worn inside the vagina

Condoms are made from thin latex or other plastics and prevent semen from coming into contact with a sexual partner. If used correctly can be up to 98% effective.


  • Protect from STIs
  • No advance preparation needed
  • Other than allergic reactions to the material, there are no medical side effects
  • Easy to get hold of and free from family planning, sexual health clinics and some GP surgeries


  • Some people find using condoms interrupts sex
  • Condoms may split, tear or slip off
  • Some people may be allergic to some of the materials used
  • Vaseline, some moisturisers/lotions can make condoms less effective
  • Condoms have a use-by date on the packaging
  • Stored in places that aren't too hot or cold and away from sharp objects

Intra-Uterine Device (IUD) and Intra-Uterine System IUS)

These two methods of contraception, commonly referred to as “the coil”, are very similar in that they are both are placed in the womb, where they serve to immobilize sperm and prevent their migration to the fallopian tubes (the area where fertilization occurs). They must be inserted by a trained professional, but once in, they are effective for 5-10 years (depending on the specific device) and are over 99% effective.

The IUD contains copper which is released locally resulting in changes in the uterus. The amount of copper released daily is less than the average dietary intake.

The IUS on the other hand, releases progestogen instead of copper. Progestogen is similar to progesterone which is naturally produced in the ovaries. The hormone thickens the mucus from the cervix and causes the womb lining to become thinner. These two actions make it less likely for sperm reaching an egg and from a fertilised egg embedding in the uterus.


  • Extremely effective
  • You don’t have to remember to take a pill every day
  • They don’t interrupt sex
  • Fertility returns when removed
  • Once fitted, they work immediately and last between 5-10 years
  • Can be used during breastfeeding
  • No evidence they increase the risk of cervical, endometrial or ovarian cancer.


  • They don’t protect against STIs
  • Periods may become heavier, irregular or longer, but this may improve after a few months
  • Damage to the uterus, or cervix during insertion. The risk is very low, but surgery may be needed to remove the device
  • Pelvic infections
  • The body may reject it
  • Increased risk of ectopic pregnancy if you get pregnant with the coil in

Vaginal Ring

This is a small, soft plastic ring placed inside the vagina and is left there for 21 days, before it is removed and replaced seven days later. It works by releasing oestrogen and progestogen, which prevents the release of an egg, prevents sperm getting to an egg and thins the womb lining making it difficult for fertilized egg to implant. This makes the vaginal ring over 99% effective.


  • It doesn’t interrupt sex
  • You don’t have to remember to take a pill every day
  • Doesn’t need a specialist to insert
  • It may reduce the risk of fibroids, ovarian cysts, ovarian, uterine and colon cancer


  • It doesn’t protect against STIs
  • Mild bleeding can occur in the first few months
  • Some women may not feel comfortable inserting or removing the ring

The Implant

This is a small tube about 4cm long that is inserted under the skin in the upper arm. It releases progestogen, which is similar to progesterone released by the body. This prevents the release of an egg from the ovary, thickens the cervical mucus and thins the womb lining, thus making it harder for sperm to move through your cervix and preventing a fertilised egg from embedding in the uterus.

It needs to be inserted by a trained professional, lasts up to three years and is over 99% effective.


  • It is very effective
  • You don’t have to remember to take a pill every day
  • It works for three years
  • Does not interrupt sex
  • Safe to use while breastfeeding
  • Fertility returns to normal when removed
  • Offer some protection against pelvic inflammatory disease and uterine cancer


  • Does not protect against STIs
  • Can cause irregular, prolonged bleeding or prevent bleeding, though these may settle after the first year
  • Side effects may include: headaches, acne, nausea, reduction in libido, though these usually stop after the first few months.
  • Risks in rare cases, include infection to the skin around the implant

Contraceptive Injection

These are injections that last between 8 - 13 weeks, depending on the type of injections. The injections contain progestogen which thickens the mucus in the cervix, stopping sperm reaching an egg and thins the uterine lining and prevents a fertilized egg from implanting in the uterus. It needs to be administered by a health professional and is over 99% effective.


  • Very effective
  • You don’t have to remember to take a pill every day
  • Lasts 8 - 13 weeks
  • Does not interrupt sex
  • May reduce heavy, painful periods
  • May protect from pelvic inflammatory disease and uterine cancer


  • Does not protect against STIs
  • Periods may become irregular, heavy, shorter, lighter or stop, though this usually settles down after the first year
  • Can take a few months for fertility to return to normal
  • Weight gain especially if already very overweight
  • Side-effects may include: headaches, acne, reduction in libido, which may improve after a few months
  • Increase the risk of osteoporosis, especially for women already at risk

Contraceptive Patch

This is a patch that sticks to the skin and releases oestrogen and progestogen. It prevents the release of eggs, it thickens cervical mucus, which prevents sperm travelling through and fertilizing an egg and it thins the womb lining, making it harder for a fertilised egg to implant. Each patch applied lasts a week before needing to be replaced and can be worn whilst showering and swimming. When used correctly, it is over 99% effective.


  • Over 99% effective if used correctly
  • Doesn’t interrupt sex
  • You don’t have to remember to take a pill every day
  • Can make periods more regular, lighter and less painful
  • May reduce the risk of fibroids, ovarian cysts, ovarian, uterine and bowel cancer


  • Does not protect against STIs
  • May be visible
  • Can potentially cause skin irritation, itching and soreness
  • Temporary side effects may include headaches, nausea and mood changes
  • Can cause some bleeding between periods in the first few cycles
  • Small increased risk of blood clots, especially if you are at a higher risk of developing this, such as a smoker, very overweight, if you have a family history of this, get migraines with aura
  • Some evidence to suggest a slightly increased risk of breast cancer compared with people who do not use hormonal contraception
  • Small increased risk of developing cervical cancer

Combined Oral Contraceptive Pill (COCP)

The “pill” is one of the most familiar contraceptive methods. It contains oestrogen and progestogen, both of which are similar to oestradiol and progesterone which are produced naturally by the body. The combined action of these hormones prevents the release of egg from the ovaries, increase the amount of cervical mucous, thereby making it harder for sperm to reach an egg and they also prevent the lining of the womb harder for a fertilized egg to embed. The pill needs to be prescribed by a health professional and when used correctly is over 99% effective.


  • Doesn’t interrupt sex
  • 99% effective when used correctly
  • Makes periods regular, lighter and less painful
  • Reduces risk of fibroids, ovarian cysts, ovarian, uterine and colon cancer

Some disadvantages of the pill include:

  • Doesn’t protect against STIs
  • You have to remember to take a pill every day
  • Temporary side effects include: headaches, nausea, and mood swings
  • Increased risk of blood clots and breast cancer
  • it can increase your blood pressure
  • Shouldn’t be used for the following women:
    • Pregnant
    • Smokers over the age of 35
    • Very overweight, diabetes, heart disease, high blood pressure or previous blood clot
    • Migraines with aura
    • History of breast cancer or strong family history of breast cancer
    • 21 days following having given birth
    • Breastfeeding until six months

Progesterone Only Pill (POP)

The POP, as the name suggests is a pill that only contains progestogen. As with all the other progestogen releasing contraceptives, this resembles progesterone that body’s hormone. This thickens the mucus in the cervix, which prevents sperm reaching an egg and also thins the lining of the womb thus preventing a fertilized egg from embedding. There are two types of POP, one that needs to be taken around the same time every day while the other type can be taken within 12 hours of the same time each day. When used correctly, the POP offers 99% efficacy.


  • Doesn’t interrupt sex
  • Can be used when breastfeeding
  • Unlike the COCP, can be used in smokers over the age of 35


  • Doesn’t protect against STIs
  • You have to take a pill every day around the same time
  • May cause irregular periods, or stop them completely
  • Temporary side-effects include: acne, headaches, weight gain and harmless ovarian cysts
  • Can’t be used in the following women:
    • Bleeding in between periods or after sex
    • History of diabetes, heart disease, stroke or blood clots
    • History of breast cancer
    • Ovarian cysts

We’ve left out natural methods, such as timing of your cycle, as they can be very inaccurate and more permanent solutions such as male and female sterilisation. This is a very broad introduction to contraception, but it should give you enough information o then go and have a chat with your doctor or visit a family planning clinic.


This blog is written by friend of Neat, Dr Nick Ambatzis MB BS, MSc (SEM), MRCGP.

Nick is a General Practitioner specialising in Sports and Exercise Medicine. He completed his medical degree at University College London Medical School in 2002. Nick worked for almost ten years as a junior surgeon and spent three years in Trauma & Orthopaedics. He attained a Masters in Sports and Exercise Medicine and subsequently trained as a GP practising in Paddington.

From an early age, Nick has been both a keen cross-country runner and water-polo player, having competed at college level. Nick is also an accomplished ultra-marathon runner, having competed in many cross-country and cross-alpine races, ranging from 50-100 miles. He has also been a Crossfit and Crossfit Endurance coach.  

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