Abortion

An abortion can occur either spontaneously, when it is called a spontaneous abortion or miscarriage, or it can be brought about by deliberate intervention, when it is called an induced abortion. The stage at which a fetus is considered viable varies according to different legislations and recommendations.

Abortion rate

The number of abortions taking place among women of reproductive age (usually 15-49), over a given period, usually a year, expressed per 1,000 women.

Abortion ratio

The number of abortions to the number of live births over a given period, described per 100 live births in a given year.

Abstinence

Abstinence is a conscious decision to avoid certain activities or behaviours. Different people have different definitions of sexual abstinence. For some, it may mean no sexual contact. For others, it may mean no penetration (oral, anal, vaginal) or only 'lower-risk' behaviours.

Abstinence-only education

Education which promotes abstinence from all forms of sexual activity until marriage, and abstinence as the only way in which HIV infections and unwanted pregnancies can be prevented.

This type of education does not discuss issues relating to contraception, sexuality or sexual and reproductive health issues which are included in comprehensive sexuality education programmes. (See also Sexuality Education).

It should be noted that abstinence is often taught as one option for safer sex in comprehensive sexuality education programmes.

Acquired immunodeficiency syndrome

The late stage of infection caused by the Human Immunodeficiency Virus (HIV). HIV steadily weakens the body's defence (immune) system until it can no longer fight off life-threatening illnesses. These include infections such as pneumonia and certain cancers.

Adolescence

The World Health Organization uses the 10-19 year age range to define adolescence.

Advocacy

A campaign or strategy to build support for a cause or issue. Advocacy is directed towards creating a favourable environment, by trying to gain people's support and by trying to influence or change legislation.

Age-sex structure

The composition of a population according to the number or proportion of males and females in each