Abstract
Using the registration of all pregnant women living within a particular geographical district of Copenhagen the risk of spontaneous abortion has been calculated by means of a decremental method. A total of 3 042 pregnancies were registered and the total risk of spontaneous abortion was calculated at 10 per cent. In 431 women the previous pregnancy had been terminated by a legally induced abortion. Increased risk of spontaneous abortion could not be demonstrated in this group, where the cumulative risk of spontaneous abortion was 12 per cent. In particular, the risk of late abortion was not seen to increase.