WASHINGTON - Women who are overweight or obese when they get pregnant are
more likely to give birth to children with congenital heart defects, according
to a U.S. government study released on Thursday.
The study, conducted by the U.S. Centers for Disease Control and Prevention,
concluded that women who were overweight or obese at the time they became
pregnant were 18 per cent more likely to give birth to babies with heart
defects, while severely obese women had a 30 per cent increased risk.
The babies had problems including obstructive defects on the right side of the
heart and defects in the tissue separating the heart's two upper chambers, the
researchers reported in the American Journal of Obstetrics and Gynecology.
"Congenital heart defects are the most common types of birth defect, and among
all birth defects, they are a leading cause of illness, death and medical
expenditures," said Dr. Edwin Trevathan, a CDC expert on birth defects and
The CDC, the U.S. government's disease watchdog, recommends that overweight
women work with their doctors to achieve a healthy weight before pregnancy.
Researchers examined the health of 6,440 infants with congenital heart defects
and 5,673 infants without problems, all of whose mothers were interviewed as
part of the CDC's National Birth Defects Prevention Study.
They assessed obesity according to each woman's body mass index, or BMI, which
relates weight to height. A woman 5 feet, 5 inches (165 cm) tall and weighing
190 pounds (86 kg) would have a BMI of 31.6, while a woman of the same height
who weighs 160 pounds (72 kg) would have a BMI of 26.6.
The researchers defined overweight as a BMI of 25 to 29.9, moderate obesity as a
BMI of 30 to 34.9 and severe obesity as a BMI of 35 or above.
The results showed links between obesity and 10 out of 25 kinds of heart
defects. Five of the 10 were associated with women who were overweight before
The study accounted for important factors such as maternal age and
race-ethnicity. Mothers who had diabetes before pregnancy, a strong risk factor
for heart defects, were excluded from the research.
Source : Reuters