What Your Sonogram Won’t Tell You
According to statistics, some 45% of U.S. mothers-to-be are overweight or obese. Now, a team of researchers at the University of Texas Southwestern Medical Center in Dallas is recommending changes in the prenatal ultrasound testing procedure to reflect that fact.
The problem is that most ultrasound equipment is designed for women with a normal body-mass index or B-M-I. Excess body mass in the form of fat can block or distort the sound waves used to form the ultrasound image – which makes the image spotty and distorted as well.
In the study, the team looked at 10,000 standard ultrasound exams and found the odds of major birth defects being visible on the ultrasound image dropped as maternal B-M-I increased.
In other words, about one out of every 100 obese mothers-to-be could end up with a sonogram that isn’t showing something important about the baby. And for diabetic women the odds are even worse – only 38% of their sonograms were able to reveal fetal abnormalities.
For now, better patient education is the only response to this problem. Standard ultrasound equipment simply isn’t designed to produce accurate images with women outside the normal BMI range, and researchers suggest that prenatal counseling for overweight or obese women should be reformulated to stress that fact.
