ABSTRACT
Ambiguous genitalia in the newborn need immediate and rational management. This complex
situation requires a strategy of clinical, hormonal, genetic, molecular, and radiographic
investigation to determine the etiology of the intersex state and orient the therapeutic
approach. Physical examination is key to diagnosis. Careful palpation to locate gonads
at the genital folds or in the inguinal region provides the first element for diagnostic
orientation. If gonads are absent, a diagnosis of female pseudohermaphroditism seems
advisable; if gonads are palpated, a diagnosis of male pseudohermaphroditism is more
appropriate. Karyotyping is systematic while polymerase chain reaction (PCR) analysis
of the SRY gene provides information about the presence of a Y chromosome within 1 day. Hormonal
investigation should be based on clinical and genetic orientation. Substantially elevated
plasma 17-OH progesterone will confirm the diagnosis of congenital adrenal hyperplasia
due to deficiency in 21-hydroxylase. Testicular stimulation with human chorionic gonadotropin
(hCG) will determine the functional value of testicular tissue. Exploration of the
genitourinary axis is principally carried out by ultrasound and genitography. By the
end of these investigations, the medical team should be able to give a precise diagnosis.
Female pseudohermaphroditism may be due to excess fetal androgens (congenital adrenal
hyperplasia), increased androgen production of maternal origin, or placental androgen
excess. In male pseudohermaphroditism, if testosterone rises normally after hCG stimulation,
androgen resistance is indicated. If it does not rise after this test, either testicular
dysgenesis or disturbance in testosterone biosynthesis may be responsible. The assignment
of sex for rearing must be guided by the etiology of the genital malformation, the
anatomic condition, and family considerations. In cases of female pseudohermaphroditism,
the newborn should always be declared to be of female sex at birth. In cases of male
pseudohermaphroditism, great care should be taken in the declaration of male sex:
the potential for reconstructive surgery and the pubertal ``programmed'' response
of the external genitalia to endogenous and exogenous testosterone are determinant.
Management of ambiguous genitalia in the newborn requires an entire multidisciplinary
team in every step of the diagnostic procedure, the choice of sex assignment, and
the treatment strategy.
KEYWORDS
Ambiguous genitalia - newborn - male pseudohermaphroditism - female pseudohermaphroditism
- management
