In 2006, the infant mortality rate was 1.9 for every 1,000 live births or babies born at 40 weeks of pregnancy. The mortality rate increased to 3.9 per 1,000 when a baby was born just a few weeks earlier at 37 weeks of pregnancy, the study found.
There were 4.1 million births in the United States in 2009 2 fewer deaths per 1000 live births would save 8000 lives.
There are about 160-170 million births per year worldwide. Infant mortality worldwide is about 43 deaths per 1000 About 6.8 million lives could be saved if the near optimal level of infant mortality could be achieved worldwide.
Preterm birth is less than 37 completed weeks of pregnancy. Until recently, babies born after 37 weeks of pregnancy were evaluated as a single, homogenous group, the March of Dimes says. The investigators found that early term infants had higher infant and neonatal mortality rates when compared to full term infants for every year from 1995 to 2006. Neonatal infant mortality rates were highest for infants born at 37 weeks of pregnancy, and declined for each additional week until 40 weeks, which had the lowest neonatal death rates. The trend was the same for all races and ethnicities. However, of the infants in the study non-Hispanic black infants had the highest infant mortality rates and the smallest declines at 37 and 38 weeks, the researchers said.