Tiny Infants, Chronic Ills?
Ironically, babies who weigh too little at birth may also be more prone to obesity and related problems later in life. In a long-term Harvard study of 70,000 nurses, women who weighed five pounds at birth were twice as likely to get heart disease as those who started life at ten pounds. Other studies have found that underweight newborns are more likely to have high blood pressure at 18 years and more likely to develop insulin resistance -- which increases the risk of diabetes -- as children. Epidemiologists suspect the fetus responds to undernutrition by becoming more efficient in its use of nutrients, which produces a child who is more prone to obesity and other metabolic problems later on.
Good nutrition during pregnancy may have multiple health benefits for mother and baby. But many other experts believe that the solution to optimal birth weight lies elsewhere. "Even if a mother eats well, she can have a small baby," says Roberts. One approach might be to reduce the rising incidence of prematurity -- since the 1980s, the preterm-birth rate has increased by 17 percent, according to the March of Dimes. But that's easier said than done.
Robert A. Barnett is Parenting's health editor.