Obesity in Pregnancy Increases Birth Defect Risk
Moms-to-be who are overweight or obese during pregnancy are at increased risk for having a baby with birth defects, according to a study recently published in the BMJ. Most health care professionals stress the importance of maintaining a healthy weight during pregnancy and earlier studies suggested a correlation between maternal obesity and birth defect risk.
In this new study, researchers took a closer look at whether expectant mothers who are overweight, rather than obese, are also at higher risk for birth defects. They analyzed information on more than 1.2 million single, live births in Sweden between 2001 and 2014. Expectant mothers in the study were classified as underweight (body mass index—BMI—of less than 18.5), normal weight (BMI of 18.5 to 24), overweight (BMI of 25 to 29), or obese (BMI over 30). Obesity was further classified as class I (BMI of 30 to 34), class II (BMI of 35 to 39), or class III (BMI greater than 40)
According to researchers, the severe birth defect rate in babies born to normal weight mothers was 3.4 percent, while the rate in overweight mothers was 3.5 percent. The rates of birth defects in babies born to obese mothers were 3.8 percent (class I obesity), 4.2 percent (class II obesity), and 4.7 percent (class III obesity).