Liberalized abortion in Oregon: effects on fertility, prematurity, fetal death, and infant death.

An analysis of Oregon Vital Statistics data from 1965 to 1975 was conducted to assess the impact of Oregon's 1969 abortion legislation, which substantially increased the number of reported medically induced abortions. This increase was associated with a slight increase in the age-adjusted 1970 fertility rate and there was no decrease in births to women in the age groups obtaining proportionately the most abortions. A significant and persistent 11 per cent reduction in premature births to women over age 20 (p less than .001) and a 22 per cent reduction in spontaneous fetal deaths (p less than .05) were associated with liberalized abortion. Decreases in neonatal and postneonatal infant mortality were observed, but were indistinguishable from an ongoing trend toward improved infant health. A gradual 25 per cent decline in the age-adjusted fertility rate occurred between 1969 and 1975, but the increase in the number of reported abortions could account for only one-fourth of this decrease. A seven-fold increase in the use of family planning clinics between 1970 and 1973 and more liberalized laws regarding provision of family planning service appeared to account for a much higher proportion of the decreased fertility than did liberalized abortion.