Ambiguous genitalia: an overview of 22 years experience and the diagnostic approach in the Pediatric Department, Siriraj Hospital.

The newborn with abnormal genital development presents a difficult diagnostic and treatment challenge for the pediatrician providing care. It is important that a definitive diagnosis be determined as quickly as possible so that the appropriate treatment plan can be established to minimize medical, psychological and social complications. The purpose of this study was to provide an extensive review of the clinical characteristics of a patient cohort with ambiguous genitalia, from 22 years' experience in the Division of Endocrinology and Metabolism, Department of Pediatrics, Siriraj Hospital, and to classify them into diagnostic categories. Moreover, a cascade of diagnostic tools in approaching sexual ambiguity in the authors' institution, starting with history and physical examination and leading to further radiographic and laboratory investigations is demonstrated and can be adopted as a guideline for the clinical management of these disorders. From 1979 to 2001, care was provided to a total of 109 patients with ambiguous genitalia, of whom 104 patients were reviewed. Among these individuals, 52 patients (50.0%) belonged to the diagnosis of female pseudohermaphroditism, 5 patients (4.8%) were in the true hermaphroditism group and the remaining 47 patients (45.2%) were in the male pseudohermaphroditism group. All female pseudohermaphrodites carried a diagnosis of congenital adrenal hyperplasia (CAH) and were reared as girls. 21 hydroxylase deficiency CAH accounted for all except one (98%) in this group. Among the 47 male pseudohermaphrodites, 9 (19.1%) had dysgenetic male pseudohermaphroditism, 7 (14.9%) had either testosterone biosynthetic defects or hCG unresponsiveness, 22 (46.8%) had either androgen insensitivity syndrome or 5 alpha-reductase deficiency, 4 (8.5%) had ambiguous genitalia in a 46,XY male associated with multiple anomalies and 5 (10.6%) had an unidentifiable cause. Sex reassignment occurred, not uncommonly, in 4 cases of female pseudohermaphrodites (7.7%) and at least 2 cases (3.9%) in the combined group of male pseudohermaphrodites and true hermaphrodites. The scope of the ambiguous genitalia problem is definitely not minor. An inappropriate approach to this problem poses an undue risk to the integrity of the physical and psychosexual health in the future for these children.