A study published in Lancet has provided convincing evidence that moms who gain a lot of weight during pregnancy give birth to heavier babies. The finding is important since high birth-weight newborns have a greater risk of becoming obese adults.
To reach these conclusions, Harvard’s David Ludwig and colleagues looked at the birth records of over one million full-term babies born in New Jersey and Michigan during a 15-year period ending in 2003. To eliminate genetic effects, the scientists only studied women that had given birth more than once.
Ludwig’s group found that the more weight women gained during pregnancy, the higher was their risk of giving birth to a high birth-weight baby (defined as 8 pounds, 13 ounces). Those who packed-on more than 52 pounds were more than twice as likely to have a high birth-weight baby as those who gained between 18-22 pounds. The latter amount is within a recommended range of pregnancy-related weight gain for overweight women.
The scientists also found that if a woman gained twice as much weight during one pregnancy as compared with another, that baby weighed about half a pound more at birth than its sibling.
Excessive weight gain during pregnancy is also dangerous for the mothers themselves: it increases the risk of gestational diabetes, the need for a Cesarean section, and pre-eclampsia, a potentially serious condition involving high blood pressure and seizures.
In addition to their increased risk for obesity in adulthood, high birth-weight newborns may also be at higher risk for allergies, asthma and cancer.
Managing weight gain “is an absolutely critical part of preconception care and prenatal care,” William Callaghan, the CDC’s chief of maternal and infant health told the Wall Street Journal.