Objective: The maternal age at child birth is increasing. If induced abortion is an important means of postponing childbirth in a population, it is to be expected that in young women the rate of conceived pregnancies is stable over time, but the induced abortion rate increases. We studied birth rates, induced abortion rates and the sum of these rates by maternal age during four decades. Design: Register-based study. Setting and population: All women 15-49 years living in Norway. Methods: We present temporal changes in birth rates and induced abortion rates within age groups during the period 1979-2007. We also estimated the sum rate of births and induced abortions. Data was obtained from national statistics.Main Outcome Measures: Live births and induced abortions per 1 000 women per year.Results: The induced abortion rates have been relatively stable within age groups, except for a decrease in women 15-19 years (from 24.2 in 1979 to 17.0 in 2007) and an increase in women 20-24 years (from 23.2 to 29.5). The birth rates however, have decreased dramatically in women 20-24 years old (from 113.6 to 60.5). Hence, the sum rate of births and induced abortions in women 20-24 years old has decreased from 136.8 to 90.0. In women 30 years old or older, the birth rates have increased. Conclusion: The induced abortion rate has been relatively stable in all age groups over time, suggesting a limited influence of induced abortions on the postponement of childbearing.
Keywords: birth rate, induced abortion rate, population study, risk factors