Aims  Lets couples (husband and wife) decide whether or not to have children and how many

Methods of birth control  Stop the sperm from reaching the egg  Stop the egg from being made, or  Stop the fertilised egg from implanting and developing in the uterus

Mechanical methods  The IUD (Intra-Uterine Device), prevent sperm pass through the uterus and may also prevent an embryo from implantation.  It also contains progesterone that makes cervix thick and sticky

Mechanical method  The cap or diaphragm, placed over the cervix before intercourse, prevents sperm enter the uterus. It should be used with sperm-killing cream or foam

Mechanical method  Condom, a thin rubber tube. It is rolled over the man’s erect penis before intercourse. It stops the sperm from entering the woman’s body. It also gives protection against STD.  Femidom, female condom and inserted into the vagina

Chemical method  The pill, an oral contraceptive as it is taken by mouth. They contain the hormones oestrogen and progesterone. There are also progesterone-only pills. These work by preventing ovulation. Has to be taken every day  Side effects: sore breasts, weight gain, depression and painful periods

Chemical methods  Spermicides are chemicals (foam, cream or jelly) that kill sperm. The woman puts the cream into her vagina before intercourse.

Natural methods  Rhythm method, it relies on when ovulation is most likely to occur and abstaining from sex in the days just before and just after that date.  A woman keeps a record of when she has her periods and then predict each month when ovulation should occur

Surgical method  Vasectomy, cut and tie the sperm duct (vas deferens).  Sterilisation (tubectomy), cut and block the oviduct.