Repeat abortion in Denmark: an analysis based on national record linkage.

The abortion registration system maintained by the Danish government permits an analysis of abortion incidence by individual. Using computer techniques to sort all the abortion records for the 15-month period from October 1973, when the abortion law was liberalized, through December 1974, it has been possible to determine the rate of repeat abortion and some demographic variables associated with it. Of the women who experienced induced abortion in the period under study, 2.92 percent had more than one abortion. Repeat abortion was found to be more frequent among women aged 20-34 and among women with a greater number of pregnancies, live births, and induced abortions prior to the change in law. A higher rate of repeat abortion was observed in urban areas. The overall rate of repeat abortion is consistent with a high level of contraceptive effectiveness.