Getting Better Some public health experts consider the rate of low birthweight to be indicative of national health, since both are affected by the same causes. If that is true, the world is getting healthier, since the LBW world average was 28 percent in 2009 but 16 percent in 2012. When all nations are included, 47 report LBW at 6 percent or less (United States and United Kingdom are not among them).