Dangers of Obesity Extend into the Womb

Women who are obese prior to pregnancy increase the risk of birth defects to their children, according to a new study published in the journal Pediatrics. In addition to regularly monitoring their weight gain during the course of their pregnancies, all women should be mindful of their body weight even before conceiving.

 

In a population-based case-control study, researchers from the Centers for Disease Control and Prevention in Atlanta, Georgia, interviewed hundreds of women to determine the relationship between prepregnancy weight and certain birth defects. They found that obese women were more likely to have an infant with spina bifida, a neural tube defect; omphalocele, a defect in the development of the abdominal wall; and heart defects. An increased risk of heart defects or other congenital anomalies was also seen in overweight mothers who did not quite meet the criteria for obesity.

The participants' weight was determined by calculating Body Mass Index (BMI), weight in kilograms divided by height in meters, squared. The risks for obese women and overweight women were compared with those for normal-weight women. Obese women were defined as those having a BMI greater than or equal to 30; overweight women were defined as those having a BMI between 25.0 and 29.9; normal-weight women had a BMI less than 24.9.

"The reason(s) for the greater risk among obese women is/are not known," explains lead researcher Cynthia A. Moore, M.D., Ph.D. of the National Center on Birth Defects and Developmental Disabilities. Dr. Moore and colleagues discuss several possible mechanisms for the correlation between excessive maternal weight and birth defects. They propose abnormalities in metabolism of glucose, insulin or hormones, which may affect the development of the fetus. They also explain that overweight women are at greater risk for gestational diabetes, or diabetes of pregnancy, which has been linked to an increase risk of birth defects. In addition, women who are pregnant require 400 micrograms of folic acid daily in order to prevent neural tube defects. The researchers suggest that heavier women may need increased requirements of certain nutrients like folic acid to prevent defects in their fetuses.

 

The incidence of obesity is on the rise in the United States and it has become increasingly clear that weight control can have a dramatic effect on the health of unborn children. "From this study, we have identified that women who are at a healthy weight before pregnancy lower their risk of having a child with certain birth defects than do women who are obese; therefore, prevention efforts should focus on attaining a healthy weight before pregnancy," according to Dr. Moore.

 

There are several other measures women can take to ensure healthy pregnancies. Dr. Moore adds, "(Women can) abstain from alcohol and smoking during pregnancy, discuss all medication use with their doctor, and take a multivitamin with (at least) 400 micrograms of folic acid daily." These simple actions can significantly improve the chances of having a healthy baby.