When mom gains too much weight during pregnancy, her child is more likely to be obese

The number of overweight children is expected to increase by 1.3 million per year worldwide, with more than 300,000 of those children becoming obese each year.

According to the Institute of Medicine, more than half of women gained excessive weight during pregnancy between 2004 and 2007.

The researchers randomly selected 5,125 children from a national database in Greece and matched them with their mothers. They conducted telephone interviews using a standardized questionnaire collecting information on the mother's age at pregnancy, amount of weight gained during pregnancy, pregnancy exercise level, smoking status, alcohol consumption and the body mass index of the child at the age of eight.

The study found that the amount of weight gained throughout pregnancy, the level of physical activity and smoking status was strongly associated with obesity in children. Moderate exercise during pregnancy was found to lower the risk of a child becoming overweight or obese in childhood, even after adjusting for the other maternal and child characteristics.

The development and introduction of specific recommendations for physical activity for pregnant women is relatively recent. Early investigations from the 1970s and 1980s were cautious about recommending that women exercise while pregnant because of limited knowledge about the response of pregnant women's bodies to exercise. Since then, researchers have begun to focus on the potential health benefits of exercise to the mothers and their babies. Currently, the American College of Sports Medicine and the American College of Obstetrics and Gynecology recommend 150 minutes of moderate exercise per week, if there are no health problems or obstetric complications.

"Pregnancy is a phase in a woman's life in which she develops a greater awareness about her health and has an important opportunity to amend some unhealthy habits, like smoking and alcohol consumption, to adopt a more active lifestyle, and to participate in physical activities and/or exercise," said UTMB's Labros Sidossis, professor of Internal Medicine and Surgery. "Health care professionals should advise expecting mothers to limit their pregnancy weight gain to the recommended range, not to smoke and consume alcohol and to engage in moderate exercise during pregnancy."