146: US neonatal mortality rates are likely lower than many high-income countries

Abstract

The US health care system has been criticized for having the highest neonatal mortality (NMR) rate among high-income countries. Rates have been combined and not been reported individually by gestational age, therefore skewing possible shifts in prematurity rates. The objective of this study was to calculate US NMR by each gestational age (GA) week. We used the 2017 linked birth/infant death records to calculate US NMR statistics for each GA week as well as birthweights. Our study shows that the NMR reported for the US by the CDC included a GA as low as 17 weeks. In addition, it included 227 neonatal deaths among 2,789 unknown gestational ages (NMR 82.28/1,000 LB). After excluding unknown gestational ages, our study shows a total NMR of 3.79/1,000 LB. For >22 weeks GA the NMR was 2.44/1,000 birth and for >23 weeks GA the NMR was 2.07/1,000 live births. NMR above 499 grams were similar to those >22 weeks GA (2.5 vs 2.4/1,000 LB). The NMR is a key outcome indicator for newborn care, and is reported regularly in comparison to other countries. In the US NMR data include all live births with gestational ages as early as 17 weeks GA. In contrast, in many other high-income countries live births before 23-24 weeks or a birthweight under 500 grams are often not included in liveborn statistics. A report from the WHO stated that “..among developed countries, neonatal mortality rates may reflect differences in the definitions used for reporting births, such as cut-offs for registering live births and birth weight. Our study shows that the US NMR for a GA of >23 weeks, similar to the methodology used by other high-income countries, is better than most other high-income countries. Even with a lower cutoff of >22 weeks, the US NMR was within the range of many European countries. This study suggests that criticism of the USA as having relatively high perinatal mortality in relation to other high income countries may be unjustified. We recommend that when comparing NMR with other countries, NMR should be clearly identified to reflect same gestational age cut-offs.View Large Image Figure ViewerDownload Hi-res image Download (PPT)