Ambiguous genitalia

The birth of an infant with ambiguous genitalia represents an emotional shock for the family, a challenge for the medical doctors and a critical situation in neonatal stage.

Individuals with a congenital discrepancy between external genitalia, gonadal and chromosomal sex, are classified as a disorder of sex development (DSD). In 2006 a new consensus about the terminology was reached, so pejorative terms like intersex, hermaphroditism and pseudohermaphroditism were abandoned. From then on, DSD is used.

DSD presents an annual incidence of 1/4500 alive newborn and the adrenal hyperplasia is the most common cause. The incidence is increased if cryptorquidia, microphallus and hypospadias are included.

The evaluation of newborns with ambiguous genitalia should be carried out as soon as possible, because the most common cause, congenital adrenal hyperplasia, can be life threatening.

The initial assessment should include physical examinations, serum electrolytes, 17-hydroxyprogesterone, cortisol, 11-deoxycortisol, 17-hydroxypregnenolone, dehydroepiandrosterone and adrenocorticotropic hormone in order to evaluate for the possibility of congenital adrenal hyperplasia. Furthermore, karyotype, SRY gen and abdominal ultrasonography must be requested.

These disorders will be classified depending on karyotype as 46XX DSD, 46XY DSD or DSD due to chromosome disorders.

The management of this situation must be performed by a multidisciplinary team (neonatologist, genetics, paediatric endocrinologist, paediatric surgeon and psychologist) in hospitals with documented experience.