Diabetic halo. A reversible ultrasonic sign

Two pregnant women with poorly controlled diabetes mellitus were noted to have "edematous" fetuses on ultrasonography. There was abdominal wall "edema" in one and scalp "edema" in both fetuses. In light of what is known about the fetal body composition in diabetic pregnancies, we propose that this sonographic appearance reflects increased fat deposition, rather than accumulation of edema fluid, in the fetal subcutaneous tissue; it has been called "diabetic halo." In a patient who had been treated for eight weeks but not in another, in whom treatment was only for 1.5 weeks, these sonographic features were reversed. This is probably in decreased fat deposition in the fetus. We suggest that this ultrasonographic sign be added to our means of diagnosing uncontrolled diabetic pregnancies and of monitoring the degree of control in diabetic pregnancies.