THE INCIDENCE OF ECTOPIC PREGNANCY IN HORDALAND COUNTY, NORWAY 1976-1993

Objective. To gain longterm knowledge of incidence rates of ectopic pr egnancy, as a basis for analysing risk factors. Material. The incidenc e of ectopic pregnancy was studied in the county of Hordaland,Western Norway, through 18 years, 1976-1993. The protocols of 1821 cases of ec topic pregnancy were registered. Population data of the county, the nu mber of births and legal abortions were available. Results. There was considerable increase in crude numbers of ectopic pregnancies througho ut the period. Grouping the cases in three six-year periods showed an increased crude incidence rate per 100 000 women from 95 during 1976-8 1 to 154 during 1988-93. The corresponding rates per 1000 births incre ased from 13.6 to 22.2 and the rates per 1000 reported pregnancies fro m 11.2 to 18.0. All rates increased also in women aged 40-44 years. Du ring the years 1979-1993 the rates per 1000 reported pregnancies incre ased by 25%, from 9.4 to 11.8 in age groups below 30 years, while the rates for women over 35 years increased by 98%, from 20.7 to 40.9. Com pared to the age group 15-19, women over 35 years had an eightfold ris k during the last period. In addition they also contributed to higher numbers of reported pregnancies by 58%. Conclusion. The rates of ectop ic pregnancy increased in age groups older than 20 years during 1976-9 3, moderately in younger age groups, but considerably in older age gro ups, who also contributed with higher total rates of pregnancy. More o lder women, with presumably accumulated risk factors getting pregnant, thus explain part of the increased rates of this disease.