Shifting age-parity distribution of births and the decrease in infant mortality.

Abstract

The infant mortality rate in the United States has declined since 1960. From 1960 to 1965 the decline was negligible and was a cause for alarm. Most of the decline has occurred since 1965. During the period 1965 to 1970 the rate dropped from about 25 to about 20 deaths per 1000 live births. Data through 1972 indicate that it is continuing to fall at the same rate. One possible explanation for the fall in infant mortality rate is related to the falling birth rate observed during the late 1960s. The decline in the overall infant mortality rate could have been caused by births proportionately shifting from high mortality risk age and birth order cells to lower risk cells. This explation thus attributes the reduction in mortality rate to planning. (Note: not family planning services necessarily but individual decisions and behavior). We will show that the changing age-birth order distribution of births since 1965 does account for about 27 per cent of the reduction in the United States infant mortality rate that has occurred. (excerpt)