Little previous research has examined changes in young women's contraceptive use after significant reproductive or health life events. Some research has examined the reasons that women might discontinue contraceptive use in general and there has been some work investigating contraceptive use after the birth of a child and after the termination of a pregnancy. However other events may also cause a woman to re-evaluate her contraception, for example, the diagnosis of an STD, or having an abnormal pap test.

The Australian Longitudinal Study on Women's Health is a broad-ranging project which examines relationships between many biological, physiological, social and lifestyle factors and women's physical health, emotional well-being, and use of and satisfaction with health services. Women were selected from the Medicare database which includes all citizens and permanent residents using stratified random sampling, with systematic over-sampling of women from rural and remote areas.

This paper presents data from 6716 women who completed a self-report survey in 1996 when they were aged 18-23, and again in 1999, 2002 and 2005. Multinomial analysis is used to explore patterns of contraceptive use before and after events related to pregnancy and birth (pregnancy, live birth, miscarriage and termination of pregnancy) and health (diagnosis with a sexually-transmitted infection and abnormal Pap test) and the factors associated with changes in contraceptive use. The ALSWH provides an exciting opportunity to examine patterns of contraceptive use over time among women of reproductive age.