The observation of ambiguous genitalia signals a medical, surgical and psychological emergency. When a baby is born with ambiguous genitalia, the normally routine announcement of the baby’s gender cannot be made to the parents, and its future identity, which is in great part based on gender, will in a very real sense be held in suspension until the most appropriate sex for rearing is chosen. Careful examination of the external genitalia of every newborn should be systematic. Although a newborn’s sex is usually evident, sometimes even slight genital malformations signal an underlying disorder that requires medical attention, and, even though rare, some malformations are so striking that the sex cannot be determined. In these cases, the medical team needs a rational and comprehensive management strategy. The most crucial decision will be the choice of sex assignment, which will depend on many complex factors.

The first step is thorough examination of the genitals. Defects, including bilateral cryptorchidism, incomplete scrotal fusion, clitoromegaly, and labial fusion, are cause for more extensive investigations and great tact in the initial wording of information given to the parents.

Rapid and precise diagnosis is essential, and a rigorous procedure for determining etiology and adequate management will have to be implemented. Ambiguous genitalia in a newborn are always profoundly distressing for parents and the pressure on the medical team to announce gender is strong. Nevertheless, this decision will have far-ranging effects and must only be made when sufficient information is available. Birth registration should be postponed until the diagnostic evaluation has enabled the most appropriate choice of sex for rearing.

A multidisciplinary team of pediatric endocrinologists, obstetricians, radiologists, surgeons, geneticists, biologists and pediatric psychiatrists working in concert is essential for the optimal management of ambiguous genitalia in the newborn. After completion of the work-up, input from all team members is important and final consensus must be sought. At this point, recommendations can be made to the family, bearing in mind the need for careful wording and the great importance of communicating that their baby will here on in have a clear and unambiguous gender. Sex assignment should be based on the potential for an unambiguous appearance, the potential for normal sexual functioning and future fertility.