Perinatal mortality and its relationship to the reporting of low- birthweight infants

Abstract

Objectives. This study examined changes in the reporting of very low- birthweight infants in Alabama from 1974 to 1994 and the impact on perinatal mortality rates. Methods. Linked live birth, neonatal death, and stillbirth records of infants born weighing less than 1500 g were compared. Results. The changes in mortality over time ranged from a drop from 100% to 92% in the under-500-g group to a drop from 39% to 4% in the 1000- to 1499-g group. The percentage of total births weighing less than 500 g increased by 155%; the percentage of 1000- to 1499-g births increased by only 7%. As a result, the percentage of neonatal mortality attributable to live births below 500 g increased from 3% to 32%. Conclusions. Increased reporting of births below 500 g has masked improvements in neonatal mortality.