Absence of Macrosomia May Be Predicted by Two Sonograms
Prediction of fetal growth not increased by large number of serial scans
MONDAY, Jan. 10 (HealthDay News) -- The absence of fetal overgrowth in women with gestational diabetes mellitus (GDM) was found to be reliably predicted by two serial sonographic abdominal circumference measurements, according to research published in the January issue of Diabetes Care.
Ute M. Schaefer-Graf, M.D., Ph.D., of St. Joseph Hospital in Berlin, and colleagues performed sonograms on 1,914 women with GDM to determine how many serial sonograms were necessary to reliably predict lack of fetal macrosomia. The women were asked to return for repeat sonograms at 3- to 4-week intervals, when fetal abdominal circumference was measured. The researched also evaluated maternal risk factors associated with macrosomia to determine whether their absence increased the scan's accuracy in predicting a non-large-for-gestational-age (LGA) neonate.
The researchers found that of the 518 women with fetal abdominal circumference > 90th percentile, the first sonogram diagnosed macrosomia in 73.9 percent of the cases. The second ultrasound diagnosed 13.1 percent of the cases (50 percent of the remainder). When the first two sonographic measurements of abdominal circumference were less than the 90th percentile, 88.0 percent of the infants were born non-LGA. In women without risk factors for macrosomia, the accuracy of prediction of non-LGA neonate was as high as 95.2 percent. Predictive ability did not improve with additional scans beyond two normal.
"We can reasonably infer from our data that additional fetal ultrasound examinations after the first two fetal ultrasound examinations suggesting normal fetal growth are unlikely to improve the ability to exclude the risk of fetal overgrowth," the authors write.