Bigger Is Better: Healthy Mom, Smart Baby
What you need to know to maximize
By Angela Pirisi published May 1, 2001 - last reviewed on June 9, 2016
The prospect of being in labor with a large baby can terrify any expectant mother. But at least now there's one reason to look forward to it: Bigger babies seem to fare better academically later in life. Plus, women can learn how to ensure their babies are born big--and how their own health can benefit too.
A report published in the British Medical Journal states that birth weight seems to be linked to how smart and academically successful a person will be, regardless of social background. The study showed a positive relationship between birth weight and cognitive ability in the 3,900 males and females who were assessed at ages 8, 11, 15 and 26. For example, males of skilled working-class background in the lightest birth weight category (5.5 pounds or less) had a 31% chance of obtaining advanced qualifications in high school or beyond, compared with 45% of males with a similar background but in the highest birth weight category (8.8 pounds or more). Generally speaking, says lead researcher Marcus Richards, a research scientist at University College in London, "A heavier birth weight translated into better intellectual performance, including better test scores and academic achievement." The researchers suggest that being heavier at birth may relate to a larger head circumference, allowing for a larger brain size.
So if bigger babes are destined to be brain surgeons or scholars, what can expectant moms do to help them grow? Exercise is one way, according to the latest findings from Case Western University, published in the American Journal of Obstetrics and Gynecology. Researchers gave 22 pregnant women an exercise regimen starting at eight weeks of pregnancy, and compared their newborns with those of 24 women who were told to do no exercise. The babies born to the moms who worked out were significantly heavier and longer compared with the newborns of the sedentary moms. "Weight-bearing exercise improves cardiovascular function in general and improves uterine blood flow and placental growth," says study author James Clapp, a professor of reproductive biology at Case Western. He adds that exercise should be at least moderately difficult to see results.
Staying fit during pregnancy is good for mom, too. A team of nutrition experts at Cornell University found that women who gain more weight during pregnancy than recommended by national guidelines are four times more likely to be obese one year after giving birth, regardless of pre-pregnancy weight.
The Institute of Medicine (IOM) suggests that having a baby should add an average of 2.2 pounds to a woman's weight a year after giving birth, but in the study, women gained an average of four pounds. That may not sound like much, says Christine Olson, a nutrition scientist at Cornell University, until you consider that 56% of new cases of obesity could have been prevented if women had stayed within the recommended weight range during pregnancy. Olson stresses that the IOM's weight gain guidelines for pregnant women are based on achieving healthy birth weights for infants, but adds that they also help women return to their normal weight. "The bottom-line message is that gaining any amount of weight in pregnancy that is within the guidelines is good for both babies and moms," she says.