Tuesday, June 19, 2007
A low birth weight increases the risk for a host of seemingly unrelated adult problems, including dropping out of high school, earning less and aging at a more rapid rate during midlife.
University of Michigan researchers tracked 12,874 people born between 1951 and 1975 for as long as 40 years; 8 percent of them weighed less than 5.5 pounds at birth.
Their study, funded by the National Institute on Aging, showed that a large part of an individual's struggle for health and wealth is decided in the womb, or even earlier. While previous studies have shown a link between low birth weight and difficulties later in life, study co-author Robert Schoeni, a professor of public policy at Michigan, said this was the most comprehensive U.S. look at the topic and the first to control for genetic factors other than those affecting birth weight: Underweight babies consistently reported poorer health and less financial success than their normal-weight siblings.
Low birth weight has been tied to delays in cognitive development, the researchers said, possibly explaining some of the later problems. Being born small begins a persistent cycle of health problems that worsens in one's 30s and 40s.
Adverse outcomes tied to low birth weight may compound over generations: Low-birth-weight women are more prone to have underweight babies, the researchers said. They also speculated that their findings may help explain familial patterns of poverty: Just as genes are passed from parent to child, wealth often is, too.
"Maybe one mechanism by which that happens," Schoeni says, "is health"-- or a close stand-in, such as birth weight.
-- Emily Lyons