By the end of the teenage years both girls and boys - from a sexual development viewpoint - have reached adulthood. This is normally achieved by age 17 for girls and age 18 for boys. Adulthood lasts until around the age of 50.

In early adulthood it is important that both men and women maintain an awareness of their own reproductive health, identifying sexual health conditions which may affect their fertility.

In middle age the reproductive capabilities, especially of women, are reduced due to a decrease in the hormonal levels of oestrogen and progesterone. For women, this phase of life is referred to as the perimenopause. The slowing down in the production of progesterone and oestrogen results in decreased fertility. The perimenopause can last for a few months or for years before the menopause begins.