Induced abortion did not increase the risk of breast cancer
To determine whether an association exists between induced abortion and the risk of breast cancer.
Cohort study of women followed up from 1968–92.
Population based study in Denmark.
All Danish women born from 1 April 1935 to 31 March 1978. In total, 1 529 512 women were included in the cohort.
Assessment of risk factors
Through a linkage with the National Registry of Induced Abortions, information on the number and dates of induced abortions was combined with information on the gestational age of each aborted fetus. The induced abortions included in this analysis were those that occurred between 1973 and 1992. Data on the obstetric history (age, parity, age at delivery of first child) were taken from the cohort database.
Main outcome measures
New cases of breast cancer identified through a linkage …