Causes of the increase in the incidence of ectopic pregnancy. A study on 1017 patients from 1966 to 1985 in Turku, Finland.

The relationship between the increased incidence of ectopic pregnancy and the known risk factors of this disorder was examined by 5-year age groups and equivalent calendar periods to determine the causes of the recent "epidemic" of ectopic pregnancy. None of the known risk factors would alone explain the observed increase. Consequently, multivariate analysis by log-linear models was applied: age, past pelvic operation, previous pelvic inflammatory disease, antecedent legal abortion, and current use of an intrauterine contraceptive device were responsible for the increase in the occurrence of the disease. The strongest association with the observed temporal trend in the increase of ectopic pregnancy was found for pelvic operation (including previous ectopic pregnancy), pelvic inflammatory disease, and current use of an intrauterine contraceptive device. Improved diagnosis and changing demographic patterns also contributed to the increase in the annual number of ectopic pregnancies.