Obesity impairs accuracy of obstetric sonography

Pregnant women who are overweight or obese are at least 10 times more likely than women of normal weight to have their fetal ultrasound screening recalled due to poor results, according to Canadian researchers.

Dr. Phyllis Glanc and colleagues at the University of Toronto assessed 100 women with a body mass index >30 who underwent routine second trimester fetal anatomic survey. They matched each case with two control subjects of normal weight and similar gestational age. They found 72% of pregnant women with high BMI had incomplete or unsatisfactory exams and about 26% required additional ultrasound scans to complete their surveys versus 2.5% of controls. Almost two-thirds of recalled exams remained categorized as having suboptimal visualization. Glanc presented the study at the 2008 ARRS meeting.