[E.E. Studentsov]

Вот такое забавное объяснение:
"Typically, several days are required to obtain the results of these diagnostic studies, while parental anxiety regarding sex assignation is unabated and an infant or child in a salt-wasting crisis can potentially decompensate. It is true that serum electrolyte measurements often offer an initial clue to the diagnosis of CAH and are rapidly available; however, they are not specific, as occurred in two of our patients (nos. 10, 14), and depending on the experience of the clinician, may not immediately point to the need for hormonal replacement therapy. Thus, the ability to reliably establish a presumptive diagnosis of CAH without waiting for the detailed biochemical data is clinically desirable, both to minimize parental stress regarding gender assignation and to expeditiously establish the need for cortisol replacement therapy. The adrenal glands are normally large in newborn infants, due to hyperplasia of the fetal cortex, and are visible on sonography of all neonates. If the sonographic findings of massive adrenal enlargement, the pathologic hallmarkand morphologic consequence of CAH, were shown to be sufficiently sensitive and distinct from normal physiologic adrenal enlargement, the diagnosis could be established without delay. However, this has not been consistent in the literature to date. To our knowledge, previous reports in this area have been few and limited, based on case reports, small numbers of patients, or retrospective analyses of the sonographic images lacking real-time information, and so far have been restricted to patients with 21-hydroxylase deficiency. These studies have reported inconclusive results on the utility of sonography in the diagnosis of infants with CAH [3, 4, 5]. In this manuscript we report the results of the prospective application of sonography to a group of male and female infants presenting with clinical suspicion of CAH, in whom the true diagnoses were later established by means of chromosomal and biochemical data.
"Pediatr Radiol. 2002 Feb;32(2):130-7. Epub 2001 Nov 29. Related Articles, Links

Sonographic findings in infants with congenital adrenal hyperplasia. Hernanz-Schulman M, Brock JW 3rd, Russell W. Pediatr Radiol. 2002 Feb;32(2):130-7