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Alternative NamesGenitals - ambiguous
Definition Return to top
Ambiguous genitalia is a birth defect where the outer genitals do not have the typical appearance of either a boy or a girl.
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. This genitalia makes it 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. For example, a genetic male may have developed the appearance of a normal female.
Typically, ambiguous genitalia in genetic females (babies with two X chromosomes) has the following features:
In a genetic male (one X and one Y chromosome), ambiguous genitalia typically include the following features:
Ambiguous genitalia is usually not life threatening (see Causes section for exceptions ), but can create social problems 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.
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.
When to Contact a Medical Professional Return to top
Ambiguous genitalia may be discovered during the first well-baby examination.
What to Expect at Your Office Visit 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 to help identify any chromosomal disorders. Questions may include:
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, abdominal or pelvic ultrasound, and 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.
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.
References Return to top
Diamond DA. Sexual differentiation: Normal and abnormal. In: Wein AJ, ed. Campbell-Walsh Urology. 9th ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 128.Update Date: 5/12/2009 Updated by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.