Ambiguous genitalia is a birth defect where the outer genitals do not have the typical appearance of either a boy or a girl.
The genetic sex of a child is determined at conception. The mother's egg cell 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 1 pair of sex chromosomes, 1 X from the mother and 1 X or one Y from the father. The father "determines" the genetic sex of the child. A baby who inherits the X chromosome from the father is a genetic female and has 2 X chromosomes. A baby who inherits the Y chromosome from the father is a genetic male and has 1 X and 1 Y chromosome.
The male and female reproductive organs and genitals both come from the same tissue in the fetus. Ambiguous genitalia can develop if the process that causes this fetal tissue to become "male" or "female" is disrupted. This makes it hard to easily identify the infant as male or female. The extent of the ambiguity varies. Very rarely, 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.
In most cases, ambiguous genitalia in genetic females (babies with 2 X chromosomes) has the following features:
In a genetic male (1 X and 1 Y chromosome), ambiguous genitalia most often include the following features:
With a few exceptions, ambiguous genitalia is most often not life-threatening. However, it can create social problems for the child and family. For this reason, a team of experienced specialists, including neonatologists, geneticists, endocrinologists, and psychiatrists or social workers will be involved in the child's care.
Causes for ambiguous genitalia includes:
Because of the potential social and psychological effects of this condition, parents should make a decision about whether to raise the child as a male or female early after diagnosis. It is best if this decision is made within the first few days of life. However, this is an important decision, so parents should not rush it.
Contact your health care provider if you are concerned about the appearance of your child's external genitalia, or your baby:
These can all be signs of congenital adrenal hyperplasia.
Ambiguous genitalia may be discovered during the first well-baby exam.
The provider will perform a physical exam which may reveal genitals that are not "typical male" or "typical female," but somewhere in between.
The provider 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 child's cheeks for this testing. Examining these cells is often enough to determine the genetic sex of the infant. Chromosomal analysis is a more extensive test 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 the internal genitals (such as undescended testes).
Laboratory tests may help determine how well the reproductive organs are functioning. This can include tests for adrenal and gonadal steroids.
In some cases, laparoscopy, exploratory laparotomy, or biopsy of the gonads may be needed to confirm disorders that can cause ambiguous genitalia.
Depending on the cause, surgery, hormone replacement, or other treatments are used to treat conditions that can cause ambiguous genitalia.
Sometimes, the parents must choose whether to raise the child as male or female (regardless of the child's chromosomes). This choice can have a big social and psychological impact on the child, so counseling is most often recommended.
Note: It is often technically easier to treat (and therefore raise) the child as female. This is because it is easier for a surgeon to make female genitalia than it is to make male genitalia. Therefore, sometimes this is recommended even if the child is genetically male. However, this is a difficult decision. You should discuss it with your family, your child's provider, the surgeon, your child's endocrinologist, and other health care team members.
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.