Subcutaneous tissue thickness cannot be used to distinguish abnormalities of fetal growth.

Two hundred forty-four women with normal pregnancies between 15-42 weeks' gestation served as a control group to determine subcutaneous tissue thickness at three different fetal locations: mid-calf, mid-thigh, and abdomen at the level of the abdominal circumference. The values at the three locations were comparable, varying between 1 mm at 15 weeks' gestation and approximately 5.5 mm at term. Similar measurements were obtained in two study groups consisting of 13 growth-retarded and 38 large for gestational age fetuses. The degree of overlap in subcutaneous tissue thicknesses between the normal group and the two groups with disturbances in fetal growth was such that neither growth retardation nor macrosomia could be reliably predicted with these sonographic measurements.