Excess weight on anyone is associated with a lot of health problems. Excess weight on a pregnant woman is associated with health problems for herself as well as for her baby. Previous research has shown that obesity among pregnant women is linked to cardiovascular problems and gestational diabetes on the maternal side that can cause pregnancy complications. Less is known about the effect of maternal obesity on the fetus but research shows that the apple does not fall far from the tree.
Women are expected to gain weight during pregnancy. However, current estimates indicate that 1 in 5 American women are obese even at the start of pregnancy and will thus gain more weight during the course of the gestation period.
A recent study showed that babies of women who were extremely overweight during pregnancy have higher chances of suffering from congenital heart defects. These are structural defects of the heart at birth and affect 8 in 1,000 newborns in the US. Congenital heart defects can be mild or life-threatening and usually require corrective surgery. Even if corrected, these defects are associated with lifetime health problems.
The researchers analyzed the health records of over 1.5 million births that took place during an 11-year period.
They compared about 7,000 women whose children were born with major heart defects to about 56,000 women whose offspring had no birth defects. The researchers calculated the mothers’ body mass index (BMI), a ratio of weight to height. A normal BMI is 18.5 to 24.9; overweight is 25 to 29.9 and obese is 30 and above. [The authors] reported that the chance of having a child with a congenital heart defect increases for obese women, and rises sharply for morbidly obese women. While moderately obese women are 11% more likely than normal-weight women to have a child with a heart defect, morbidly obese women are 33% more likely. Women who were overweight but not obese had no increased risk.
According lead author Dr. James L. Mills, researcher at Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD):
“The trend is unmistakable: The more obese a woman is, the more likely she is to have had a child with a heart defect. If a woman is obese, it makes sense for her to try to lose weight before becoming pregnant. Not only will weight loss improve her own health and that of her infant, it is likely to have the added benefit of reducing the infant’s risk for heart defects.”
Other infant conditions linked to maternal obesity are type 2 diabetes and neural tube defects.