Rantakallio P (Department of Public Health Science, University of Oulu, 90220 Oulu, Finland) and Myhrman A. Changes in fertility and the acceptability of pregnancies in Northern Finland during the last 20 years, International Journal of Epidemiology, 1990, 19; 109-114.The acceptability of pregnancies was studied in two birth cohorts in Northern Finland which represent 96% of all births in the region in 1966 (12 068 births) and 99% (9362 births) in 1985-1986. The numbers of women of fertile age in the area during these years were 148 000 and 158 000, so that fertility may be said to have fallen from 81 to 59 per 1000.The pregnancy was wanted in 63.0% of cases and unwanted in 12.2% in 1966, the rest being classified as accepted later. The corresponding figures in 1985-1986 were 91.8% and 1.0%. The latter figures changed very little when maternal age, parity and social class were standardized to the 1966 levels. Acceptability was connected with age, in that the age groups in which childbearing was most frequent, 20-25 years in 1966 and 26-30 years in 1985-1986. had the highest incidence of desired pregnancies. In spite of the fact that there were 1. 4 times as many births per woman aged 15-49 years in the former cohort, more wanted children were born to the age group 25-34 years in the latter cohort. The percentage of wanted pregnancies also varied with the woman's parity, social class and marital status. The children in the 1966 cohort were followed until the age of 14 and the incidences of cerebral palsy (CP) and mental retardation (IQ<71) were 3. 2 times higher among the unwanted children than among the wanted ones. After standardization for maternal age, parity, marital status and years of schooling and paternal social class by logistic regression analysis, unacceptability still increased the risk of CP significantly (p=0.013) and that of mental retardation almost significantly (p=0.052).When the fertility for 1966 was calculated with the number of pregnancies judged by the women to be acceptable later or unwanted adjusted to the same level as in 1985-1986 the fertility was the same as in 1985-1986. The reasons for the decrease in fertility and increased proportion of wanted pregnancies can therefore be assumed to lie in improved contraceptive methods and a freer attitude towards these and especially towards legal abortions. The number of legal abortions had increased from 65 to 200 per 1000 births between the two periods studied. © 1990 International Epidemiological Association.
