In order to demonstrate the detailed profile of the recent epidemic of ectopic pregnancy and the subsequent decrease of the disease, the authors analyzed the changes in 5-year age groups and by 5-year age cohorts in Finland. The results describe a link between the epidemic of ectopic pregnancy and the so-called "baby boom" cohort (from 1945 to 1954) in the 1970s and 1980s, when these large age groups were in their most fertile period. The authors conclude, through its risk factors, that ectopic pregnancy is strongly correlated with age and that it exemplifies how the changes caused by large age groups play a role in the rise and fall in occurrence of certain diseases.