Ambiguous genitalia is a rare condition where a child is born with outer genitals that do not clearly look either male or female. They may have features of both sexes or not be fully developed. The characteristics of the child's genitals may not match their internal sex organs or their genetic sex.
This condition is also called uncertain genitalia or atypical genitalia.
Ambiguous genitalia is common in children with differences of sex development (DSD).
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 1 Y from the father. A baby who inherits the X chromosome from the father has 2 X chromosomes and is a genetic female. A baby who inherits the Y chromosome from the father has 1 X and 1 Y chromosome and is a genetic male.
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 means the external genitals do look clearly male or female or may have characteristics of both. The physical appearance of people with this condition can vary widely. 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 female.
In most cases, ambiguous genitalia in genetic females (infants with 2 X chromosomes) has the following features:
- An enlarged clitoris that looks like 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 and look like 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 (1 X and 1 Y chromosome), ambiguous genitalia most often include the following features:
A small penis (less than 2 to 3 centimeters, or 3/4 to 1 1/4 inches) that looks like 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 (hypospadias). It can be located as low as the perineum, further making the infant appear to be female.
There may be a small scrotum that is separated and looks like labia.
Undescended testicles commonly occur with ambiguous genitalia.
With a few exceptions, ambiguous genitalia is most often not life-threatening. However, its treatment has short- and long-term consequences. For this reason, a team of health care professionals with expertise in DSD will work together to understand and treat the child and support the family. This team may include neonatologists, geneticists, endocrinologists, and psychiatrists or social workers. The specific treatment will depend on the specific cause of the ambiguous genitalia.
Causes for ambiguous genitalia include:
- 46, XX disorder of sex development (DSD) and 46, XY DSD. The genitalia are of one sex, but some physical characteristics of the other sex are present.
- Ovotesticular DSD. This is a very rare condition, in which tissue from both the ovaries and testicles is present. The child may have parts of both male and female genitals.
- Congenital adrenal hyperplasia. This condition has several forms, but the most common form causes a genetic female to appear male. Infants are tested for this potentially life-threatening condition during newborn screening exams.
- Chromosomal abnormalities, including Klinefelter syndrome (XXY) and Turner syndrome (XO).
- If the mother takes certain medicines (such as androgenic steroids), a genetic female may look more male.
- Lack of production of certain hormones can cause the embryo to develop with a female body type, regardless of genetic sex.
- Androgen insensitivity syndrome. Even if the body makes the hormones needed to develop into a physical male, the body does not respond normally to those hormones. This may produce female characteristics, even though the genetic sex is male.
When to Contact a Medical Professional
Contact your health care provider if you are concerned about the appearance of your child's external genitalia, or your baby:
- Takes more than 2 weeks to regain his or her birth weight
- Poor feeding or vomiting
- Looks dehydrated (dry inside of mouth, no tears when crying, less than 4 wet diapers per 24 hours, eyes look sunken in)
- Has a decreased appetite
- Has blue spells (may indicate short periods when a reduced amount of blood flows into the lungs)
- Has trouble breathing
These can all be signs of congenital adrenal hyperplasia.
Ambiguous genitalia may be discovered during the first well-baby exam.
What to Expect at Your Office Visit
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:
- Is there any family history of miscarriage?
- Is there any family history of stillbirth?
- Is there any family history of early death?
- Have any family members had infants who died in the first few weeks of life or who had ambiguous genitalia?
- Is there any family history of any of the disorders that cause ambiguous genitalia?
- What medicines did the mother take before or during pregnancy (especially steroids)?
- What other symptoms are present?
The following tests may be done:
- Chromosome analysis (karyotyping) to determine the person's genetic makeup
- Blood tests to check levels of testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH)
- Electrolyte tests
- Specific molecular testing
Depending on the cause, surgery, hormone replacement, or other treatments are used to treat conditions that can cause ambiguous genitalia.
There have been significant changes in treating ambiguous genitalia. In the past, it was thought that it was best to assign a gender as quickly as possible. This was often based on the external genitals rather than the chromosomal gender. Expert opinion has shifted to understanding that chromosomal, neural, hormonal, psychological, and behavioral factors can all influence gender identity.
Many experts now urge delaying definitive surgery for as long as is healthy, and ideally involving the child in the decision, unless surgery is needed for the health of the infant. Working with your child’s heath care team can help you make the best choices for your child. In addition, a DSD support group can help provide families with the latest research and offer a community of other families, children, and adult individuals who have faced the same issues.
Genitals - ambiguous; Uncertain genitalia; Atypical genitalia
Fischer KM, Kolon TF. Embryology and differences of sex development. In: Guzzo TJ, Wein AJ, Kovell RC, Weiss DA, Ziemba JB, eds. Penn Clinical Manual of Urology. 3rd ed. Philadelphia, PA: Elsevier; 2024:chap 25.
Vilain E, Shimy K. Differences of sex development. In: Robertson RP, ed. DeGroot's Endocrinology. 8th ed. Philadelphia, PA: Elsevier; 2023:chap 101.
White PC. Congenital adrenal hyperplasia and related disorders. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 594.
White PC. Sexual development and identity. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 214.
Yu RN, Diamond DA. Disorders of sexual development: etiology, evaluation, and medical management. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh-Wein Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 48.
Review Date 4/25/2023
Updated by: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team. Editorial update 01/17/2024.