Ambiguous Genitalia

Ambiguous genitalia is a rare birth defect in which a baby’s external genitals aren't clearly male or female.

The genitals may not be well formed, or the baby may have characteristics of both sexes. The outer genitalia may not match the internal sex organs.

The condition, a disorder of sexual differentiation, affects an estimated 1 in 4,500 infants.

What determines the sex of a baby?

A baby's genetic sex is partially determined at conception when the child inherits a pair of sex chromosomes – an X from the mother and either an X or Y from the father. If the baby inherits an X chromosome from both parents, it is a genetic female (XX). If the baby inherits the Y chromosome from the father, the baby is a genetic male (XY chromosomes).   Hormonal influence in utero also plays a role in sex determination and reproductive development.

With ambiguous genitalia, problems in the development of the fetus can result in external genitals that don’t match the baby’s chromosomal sex (XX or XY).

Patients can be seen by Texas Children's experts in Pediatric and Adolescent Gynecology.

Causes & Risk Factors

A genetic female (XX chromosomes) may develop ambiguous genitalia if male hormones are present. Possible causes include:

• Congenital adrenal hyperplasia (CAH) – acondition in which the body produces too much of a male sex hormone, causing virilization in females
• Prenatal exposure to certain drugs with hormonal effects – such assteroids that can cause developing female genitals to become more masculine
• Tumors– in the fetus or the mother, which can produce male hormones
• Family history of CAH
• Genetic abnormalities

Symptoms & Types

Symptoms in genetic females (XX chromosomes) may include:

• Enlarged clitoris that looks like a small penis
• The urethral opening, where urine comes out, is above, below or along the clitoris
• The labia is closed together, or has folds and looks like a scrotum
• Lumps in the labia, making it look more like a scrotum with testicles

Diagnosis & Tests

 In most cases, ambiguous genitalia is diagnosed at birth or during the baby’s first well visit.

Diagnosis starts with a thorough medical history and physical exam.

Diagnostic testing may include:

• Blood and urine tests to measure hormone levels
• Chromosome analysis to determine the genetic sex (XX or XY)
• Ultrasound, x-ray or other imaging tests to create images of the internal reproductive organs
• Laparoscopy – procedure in which thin tube with a camera on the end (laparoscope) is inserted through a small incision in the abdomen to view internal organs
• Biopsy – removal of a small tissue sample for examination under a microscope

Treatment & Care

Treatment depends on the individual and their symptoms. Treatment strategies include:

• Medications – such ashormone replacement therapy to correct any hormonal imbalance
• Surgery – to correct the function and appearance of the genitals and improve fertility
• Counseling – to help the girl and her family deal with the emotional and psychological challenges of ambiguous genitalia

Ambiguous genitalia is a rare and complex condition requiring specialized expertise in disorders of sexual differentiation and a team of specialists – including neonatologists, geneticists, gynecologists, urologists, endocrinologists,  psychiatrists  and social workers – all working together to improve the girl’s physical and emotional well-being.