Controlling Fertility

Reducing fertility

• Oestrogen can be used to prevent the release of an egg- so it can be used as a method of contraception.
• This may seem strange because normally oestrogen stimulates the release of eggs, but if oestrogen is taken every day to keep levels permanently high, it can inhibit production of FSH. This means after a while egg development and production stop and stay stopped.
• Progesterone also reduces fertility, e.g. by stimulating the production of thick mucus which prevents any sperm getting through and reaching an egg.
• The pill is an oral contraceptive continaining both oestrogen and progesterone (known as the combined oral contraceptive pill).
• It is over 995 effective at preventing pregnancy, but it can cause side effects such as headaches and nausea, as well as not protecting against STDs.
• There's also a progesterone only pill that has fewer side effects than the combined oral contraceptive pill and is just as effective.
• Other methods of contraceptions use hormones, like: the contraceptive patch, which contains oestrogen and progesterone in a small 5cm x 5cm patch that lies under the skin, lasting about a week.
• The contraceptive implant is inserted under the skin of the arm. It releases a continuous flow of progesterone stopping the ovaries producing eggs, making it hard for sperm to swim, and stopping any fertilised egg implanting in the uterus. An implant can last for three years.
• The contraceptive injection also contains progesterone. Each dose lasts 2-3 months.
• An IUD (Intrauterine device) is a T-shaped device that is inserted into the uterus to kill sperm and prevent implantation of a fertilised egg. There are two main types: plastic IUDs that release progesterone, and copper IUDs that prevent the sperm surviving in the uterus.

Barrier methods

• Non-hormonal forms of contraception are designed to stop the sperm from getting to the egg.
• Condoms are worn over the penis during sexual intercourse to prevent the sperm entering the vagina. There are also female condoms that are worn inside the vagina. Condoms are the only type of contraception that will protect against STDs. 
• A diaphragm is a shallow plastic cup that fits over the cervix (the entrance to the uterus) to form a barrier. It has to be used with spermicide, a substance that disables or kills the sperm.
• Spermicide alone can be used as a form of contraception, but…