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The biology of controlling fertilityFertility

Fertility is the ability to produce offspring. Fertility is continuous in males and cyclical in females. Infertility can have a number of causes and there are a range of infertility treatments that work in different ways. Physical and chemical methods of contraception can prevent fertilisation and pregnancy.

Part of Human BiologyPhysiology and Health

Fertility

Fertility is the ability to produce offspring.

Continuous fertility

In men, fertility is continuous. Levels of testosterone, and are kept relatively constant through negative feedback. As a result, sperm are produced continually.

Cyclical fertility

In women, fertility is cyclical. Levels of oestrogen, progesterone, and fluctuate. As a result women are only fertile for a small number of days before and after ovulation during each menstrual cycle.

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Identifying the fertile period

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