Decrease in infant mortality in New York City after 1989

Objectives. This study identified factors contributing to the rapid decline in infant mortality in New York City from 1989 to 1992. Methods. Changes in birthweight distributions and in birthweight/age-, cause-, and birthweight/age/cause-specific mortality rates from 1988/89 (before the mortality reduction) to 1990/91 were identified from New York City vital statistics data. Results. Infant, neonatal, and postneonatal mortality of very-low-birthweight (<1500 g) and normal-birthweight infants decreased significantly. The declines were almost entirely due to decreases in birthweight-specific mortality rates, rather than increased birthweights. All races experienced most of these reductions. Mortality decreased significantly for 6 causes of death. These decreases were consistent with the birthweight/age groups experiencing mortality declines. Conclusions. Widespread, multiple perinatal and postnatal factors contributed to the declined in infant mortality.