Ultrasonographic evaluation of adrenal involution during antenatal and neonatal periods

Using real-time ultrasonography, 25 adrenal glands from prenatal to neonatal periods were prospectively examined to assess the process of shrinkage. A similar sonographic structure was seen in both prenatal and neonatal adrenal glands. The area of adrenal gland (AGA) and the rate of decrease were calculated during antenatal and early neonatal periods. The values of AGA were 350 +/- 19 mm2 within a week of delivery, 304 +/- 17 mm2 (87 +/- 2%) just after delivery, 273 +/- 25 mm2 (77 +/- 5%) on the 1st day, 246 +/- 24 mm2 (70 +/- 5%) on the 2nd day, 215 +/- 23 mm2 (61 +/- 5%) on the 3rd day, 196 +/- 22 mm2 (56 +/- 5%) on the 4th day, 173 +/- 18 mm2 (50 +/- 4%) on the 5th day, 154 +/- 14 (44 +/- 4%) on the 6th day, 140 +/- 12 mm2 (40 +/- 2%) on the 7th day, respectively. In conclusion, the postnatal involution of the adrenals was documented by ultrasound.