CPIPRRecent research suggests that if rates of obstetric practices had not changed between 1990 and 2013, then the average U.S. birth weight would have increased over this time.
Worth the Weight? Recent Trends in Obstetric Practices, Gestational Age, and Birth Weight in the United States - PubMed
Birth weight in the United States declined substantially during the 1990s and 2000s. We suggest that the declines were likely due to shifts in gestational age resulting from changes in obstetric practices. Using restricted National Vital Statistics System data linked birth/infant death data for 1990 …