According to a research report, overweight and obese women have less chance to receive an accurate reading from ultrasound screenings aimed at identifying fetal abnormalities. This effect is also seen in among women who are diabetic prior to their pregnancy. The study analyzed more than 10,000 standard ultrasound exams and more than 1,000 specialized ultrasound exams for high-risk pregnancies. The researchers used data from previously performed study that looked at a total of 12,200 ultrasounds between 2003 and 2007, among women entering their 18th to 24th week of pregnancy, to explore the degree to which ultrasound results are sensitive to BMI. The majority of both standard-risk and high-risk pregnant women were Hispanic (about 87 percent), with about 10 percent participants being black and 2 percent being white. Stacking ultrasound results up against both the mother's BMI and infant discharge records, the research team noted the 20 percent weight-linked plunge in ultrasound effectiveness. That translated into a significant rise in risk that a child would be born with a major birth defect despite the fetus having appeared normal during an ultrasound. Apart from the BMI effect, the authors also found that among cases deemed to face a particularly high risk for fetal abnormalities prior to undergoing a screening, ultrasound mistakes were more likely to occur among women who had been diabetic prior to their pregnancy than among women with other high-risk indications. In fact, diabetic women were found to experience only a 38 percent success rate in spotting fetal abnormalities via ultrasound, compared to the 88 percent success rate experienced among women burdened with other sorts of high-risk factors.