The independent variables available in the data included place of residence, age, age at marriage, education level, children ever born, prior experience of abortion or stillbirth, and contraceptive use prior to pregnancy, which are found to be correlated with pregnancy intention. In the ILFS data, in addition to these variables, the region of residence (four selected provinces) was added to the analysis, and "children ever bom" was replaced by pregnancy order. The ILFS further provides information that allows for exploration of the association between pregnancy intention and the outcome of pregnancy in relation to the timing of pregnancy. Pregnancies are divided into three cohorts, those that occurred at an early age (15-24 years) before 1985, during the period from 1985 to 1994 and during the period from 1995 to 2005.