Issue 160

Guide to Contraception

19th November 2007

The Pill

A contraceptive pill consisting of oestrogen and progesterone, or a 'mini-pill' of just progesterone. Taken daily, it can prevent ovulation and changes the lining of the uterus to make implantation difficult if not impossible.

Effectiveness: Theoretically, 99.9%. However, progesterone-only pills are slightly less effective. Effectiveness can also be decreased if the pills are missed or not taken at the same time every day. Being overweight can lessen the effectiveness as well. The Pill is most effective when used with condoms or spermacide, although many women do not feel the need to use another method.

Risks: Vary. Smokers are at a risk of stroke which increases as they get older. People with high blood pressure or frequent migraines should also avoid the pill for the same reason. Different pills effect people differently, Some women have trouble with the Pill while others do not, and some are at higher risk of adverse side effects. These hormones are also available in the form of implants, patches, and cervical rings, all with very similar rates of effectiveness and potential side effects.

Depo-Provera

This is a hormonal shot usually given in the arm once every three months. It works by causing infertility for a three month period, during which time you will usually not get a period. GPs have been keen on offering this in recent years, although for most people, the risks far outweigh the benefits.

Effectiveness: 99.9% Actually slightly more effective than the Pill.

Risks: Many. The same as the pill, but worse. If any adverse reactions are experienced, the hormones will not leave your body for three months: there is no way to get them out. If you manage to get pregnant while on Depo-Provera, which is uncommon but has happened, you will probably have no way of knowing for at least three months.

Condoms

The most widely used contraceptive in the world, and have been for centuries. Protect against STIs as well as pregnancy. Usually made of latex, they fit over the erect penis and act as a semen receptacle.

Effectiveness: Very high if used properly. They must be stored in temperature-controlled environments, must be used before their expiry dates, must be kept within their packages and protected from holes or tears, must not be used with any oil-based lubricants, and must be put on correctly. Effectiveness increases if used with another method of birth control, such as spermacide or a hormonal method.

Risks: No adverse health risks, unless either partner is allergic to latex. If this is the case, polyurethane condoms are also available from most chemists.

Spermacides

Chemicals which block and often destroy sperm. Must be put as close to the cervix as possible in order to prevent sperm from getting through. The most effective spermacides contain a high amount of nonoxynol-9. They come in several different forms: foam, film, cream, and jelly. The most effective of these is the foam as it fills the whole vagina. Spermacide, like condoms, must be used before the expiry date.

Effectiveness: Not very high when used alone (foam is about 75%), but effectiveness increases when used with other methods.

Risks: No real health risks, although there is a risk of allergic reaction (usually no more serious than itching) or more common Urinary Tract Infections.

Intrauterine Device (IUD or Coil)

A small copper wire device which is fitted and left in the uterus. Prevents pregnancy by changing the lining of the uterus so that implantation is impossible. Copper can also kill sperm. Must be replaced by your doctor every five years.

Effectiveness: 96-99%. Effectiveness increases with use of condoms during fertile days.

Risks: High risk of ectopic pregnancy, septic miscarriage (in some older models), pelvic inflammation, blood clots, painful or heavier periods, and an increased risk of contacting STIs if exposed. There is also a risk of lasting infertility, which is why IUDs aren't usually given to young women.

Withdrawl

This involves literally withdrawing the penis before ejaculation occurs. This is very commonly practiced.

Effectiveness: Almost non-existent. In theory, pregnancy should not occur if there is no ejaculation. However, pre-ejaculatory fluid is emitted and this usually contains a small amount of active sperm. Partial ejaculation is also possible. Also, due to the often sudden and involuntary nature of ejaculation, it is very difficult to withdraw before it occurs.

Risks: Frequent pregnancy. No real health risks.

Jess Ramthun