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Alternative names
Genitals - ambiguousDefinition Return to top
A birth defect where the outer genitals do not have the typical appearance of either sex. (See also genetics)Considerations Return to top
The genetic sex of a child is determined at conception. The mother's egg cell (ovum) contains an X chromosome, while the father's sperm cell contains either an X or a Y chromosome. These X and Y chromosomes determine the child's genetic sex. Normally, an infant inherits ONE PAIR of sex chromosomes -- one X from the mother and one X or one Y from the father. Thus, it is the father who "determines" the genetic sex of the child. A baby who inherits the X chromosome from the father is a genetic female (two X chromosomes). A baby who inherits the Y chromosome from the father is a genetic male (one X and one Y chromosome).
The male and female reproductive organs and genitals both arise from the same tissue in the fetus. If the process that causes this fetal tissue to become "male" or "female" is disrupted, ambiguous genitalia can develop.
Ambiguous genitalia are those in which it is difficult to classify the infant as male or female. The extent of the ambiguity varies. In very rare instances, the physical appearance may be fully developed as the opposite of the genetic sex (e.g., a genetic male may have developed the appearance of a normal female).
Typically, ambiguous genitalia in genetic females (babies with two X chromosomes) include an enlarged clitoris that has the appearance of a small penis. The urethral opening (where urine comes out) can be anywhere along, above, or below the surface of the clitoris. The labia may be fused, resembling a scrotum. The infant may be thought to be a male with undescended testicles. Sometimes a lump of tissue is felt within the fused labia, further making it look like a scrotum with testicles.
In a genetic male (one X and one Y chromosome), ambiguous genitalia typically include a small penis (less than 2-3 centimeters or 0.8-1.2 inches) that may appear to be an enlarged clitoris (the clitoris of a newborn female is normally somewhat enlarged at birth). The urethral opening may be anywhere along, above, or below the penis; it can be placed as low as on the peritoneum, further making the infant appear to be female. There may be a small scrotum with any degree of separation, resembling labia. Undescended testicles commonly accompany ambiguous genitalia.
Ambiguous genitalia is usually not life threatening (see Causes section for exceptions), but can create social upheaval for the child and the family. For this reason, a team of experienced specialists, including neonatologists, geneticists, endocrinologists, and psychiatrists or social workers will be involved.
Common Causes Return to top
Home Care Return to top
Because of the potential social and psychological effects of this condition, the decision to raise the child as male or female should be made early after diagnosis, preferably within the first few days of the infant's life.Call your health care provider if Return to top
Ambiguous genitalia may be discovered during the first well-baby examination.
What to expect at your health care provider's office Return to top
The doctor will perform a physical examination, which may reveal a genital structure that is not "typical male" or "typical female," but somewhere in between. The doctor will ask medical history questions, such as:
DIAGNOSTIC TESTS
Genetic testing can determine if the child is a genetic male or female. Often a small sample of cells can be scraped from inside the cheeks (this is called a buccal smear); examination of these cells is often sufficient to determine the genetic sex of the infant. Chromosomal analysis is a more extensive cell study that may be needed in more questionable cases.
Endoscopy, abdominal X-ray, or similar tests may be needed to determine the presence or absence of internal genital structures (such as undescended testes).
Laboratory tests may help determine the functioning of reproductive structures, including tests for 17-ketosteroids.
In some cases, laparoscopy, exploratory laparotomy, or biopsy of the gonads may be necessary to confirm disorders associated with ambiguous genitalia.
TREATMENT
Depending on the cause, surgery, hormone replacement, or other treatments are used to treat conditions associated with ambiguous genitalia.
Sometimes, the ambiguity is such that a choice must be made whether to raise the child as male or female (regardless of the child's chromosomes). This choice can have tremendous social and psychological impact on the child, so counseling is usually recommended.
Note: It is often technically easier to treat (and therefore raise) the child as female (it is easier for a surgeon to make female genitalia than it is to make male genitalia), so in some cases this is recommended even if the child is genetically male. However, this is a difficult decision and should be discussed with your family, your doctor, and the surgeon involved.
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Page last updated: 28 October 2004 |