KidsMD Health Topics

Ambiguous Genitalia

  • When a baby is born, "girl or boy?" is the question on the tip of everyone's tongues. Discovering that your newborn has ambiguous genitalia can be emotionally traumatizing and confusing for you and your family. Ambiguous genitalia are sexual organs that aren't well formed or aren't clearly male or female.

    • An estimated 1 in 4,500 infants are born with ambiguous genitalia.

    • It's important not to try to guess the baby's gender. Tests will most likely determine the cause of the problem and the sex of boy or girl. Results should come back in a few days, or at the most, one or two weeks.

    • With few exceptions, babies with ambiguous genitalia are physically healthy.

    • Ambiguous genitalia can signal a medical emergency if the condition is the result of a rare form of a genetic disorder called congenital adrenal hyperplasia.

    How Boston Children's Hospital approaches ambiguous genitalia

    Children's is also home to the Gender Management Service (GeMS) Clinic, which treats the medical and psychosocial issues of infants, children, adolescents and young adults with disorders of sexual differentiation.

    Contact Us

    The GeMS Clinic

    GEMS treats the medical and psychosocial issues of infants, children, adolescents and young adults with disorders of sexual differentiation.

    Boston Children's Hospital
    300 Longwood Avenue
    Fegan 5
    Boston, MA  02115


  • What are ambiguous genitalia?

    At conception, a fetus's gender is already determined based on the 23rd pair chromosome it inherited from the parents. Females have two X chromosomes and males have an X and a Y chromosome. Even though the gender is set, the fetal tissue that will eventually become the female ovaries or male testes (gonads) has not yet begun to take its form. If the hormonal process that causes that tissue to become male or female is disrupted over the following weeks, ambiguous genitalia can develop.

    Your obstetric team will most likely be the first ones who notice the ambiguous genitalia. They may see the following:

    Characteristics of ambiguous genitalia in genetic females include:

    • an enlarged clitoris, or what appears to be a small penis
    • a concealed vagina

    Characteristics of ambiguous genitalia in genetic males include:

    • hypospadias, the condition in which the narrow tube that carries urine and semen (urethra) doesn't fully come to the tip of the penis

    • an abnormally small penis with the urethral opening nearer to the scrotum

    • no recognizable male genitalia in the most severe cases

    • the absence of both testicles in what appears to be the scrotum

    What causes ambiguous genitalia?

    The sexual organs of males and females develop from the same fetal tissue. The same tissue that becomes a penis in a male becomes a clitoris in a female. The main factor controlling the next step is male hormones. The presence of male sex hormones causes male organs to develop and the absence of male hormones causes female organs to develop.

    Without enough male hormones, a genetic male will develop ambiguous genitalia. Likewise, a genetic female will develop ambiguous genitalia if male hormone is present.

    Possible causes of ambiguous genitalia in genetic females:

    • Congenital adrenal hyperplasia (CAH)
      • Certain forms of this genetic condition cause the adrenal glands to make excess male hormones (androgens).

      • Congenital adrenal hyperplasia is the most common cause of ambiguous genitalia in newborn females. Males aren't born with ambiguous genitalia, but they may have unusually fast development and virility problems.

      • CAH is present in about one in 15,000 newborns.

      • Another type of CAH, called "salt-losing," is a potentially life-threatening enzyme deficiency. Male and females are equally affected. Treatment is available if diagnosed early.

      • In some cases, if the fetus is female, the mother of a fetus with CAH can be given medications during pregnancy to lessen the effects of the enzyme deficiency.

      • CAH is a recessive gene, meaning that each parent carries one copy of the gene and transmits the gene at the same time to the child. Carrier parents have a 25 percent chance with each pregnancy of having an affected child.

    • The mother's ingestion of a substance with male hormone activity
      • for example, progesterone (taken in the early stages of pregnancy to stop bleeding)
    • Tumors in the fetus or the mother that produce male hormones

    Possible causes of ambiguous genitalia in genetic males:

    • impaired testicle development caused by genetic abnormalities or unknown causes
    • Leydig cell aplasia, a condition that impairs testosterone production
    • Androgen insensitivity syndrome
      • If a male child has partial androgen insensitivity syndrome, he will exhibit ambiguous genitalia. Androgen sensitivity syndrome is a condition in which developing genital tissue is unable to respond to normal male hormone levels.

    • 5alpha-reductase deficiency, an enzyme deficiency that impairs normal male hormone production

    • The mother's ingestion of substances with female hormone activity

      • for example, estrogens, or anti-androgens. This is unusual, but could occur if a woman taking birth control pills gets pregnant despite taking the pills. Then, not knowing she's pregnant, she continues taking the pills into pregnancy for several weeks. Also some "nutritional supplements" contain plant estrogens.

    What is the long-term outlook for a child with ambiguous genitalia?

    Some children born with ambiguous genitalia have normal internal sexual organs that allow them to live a fertile reproductive life. Others may be infertile or experience difficulty conceiving a child. Sometimes there is an increased risk of tumors in the gonads later in life.

  • How does physician determine the gender of an infant with ambiguous genitalia?

    Our physicians, along with you, will consider the following:

    • a pelvic ultrasound (to check for the presence of female reproductive organs)
    • a genitourethrogram to look at the urethra and vagina if present
    • a chromosomal analysis (to help determine genetic sex: 46, XX or 46, XY)
    • fertility potential of a female pseudohermaphrodite
    • size and potential for growth of a penis present in a male pseudohermaphrodite
    • ability of an internal reproductive organ to produce appropriate sex hormones for the gender
    • risk of future health conditions, such as cancer, that may develop in the original reproductive organs later in life
    • the actions of male or female hormones on the fetal brain
    • your opinion or preference
  • Treatment for ambiguous genitalia depends on the underlying disorder.

    • Assigning the gender is important for treatment purposes and for the emotion well being of the child.
    • Usually, treatment involves performing corrective surgery to remove or create the appropriate sexual organs.
    • Hormone replacement therapy (HRT) could also be a part of the treatment process.

    Ambiguous genitalia treatment at Boston Children's Hospital

    At Boston Children's Hospital, a team of health care providers and you will determine the appropriate sex assignment. This determination will inform the course of treatment. You, as parents, will be involved every step of the way.

    The Gender Management Service Clinic (GeMS) is designed to address psychosocial issues that may arise from ambiguous genitalia. Our treatment team includes urologists, endocrinologists and geneticists, as well as a research psychologist, social workers and nurses who run support groups.

    In the past, disorders of sexual differentiation like ambiguous genitalia were seen as medical emergencies that needed to be addressed immediately. Parents were not always involved in the decision-making process, which varied from center to center. In recent years, however, adult patients have formed national advocacy groups that have changed the thinking about how to manage ambiguous genitalia. At the GeMS, families are intimately involved in the life-changing decisions.

Request an Appointment

If this is a medical emergency, please dial 9-1-1. This form should not be used in an emergency.

Patient Information
Date of Birth:
Contact Information
Appointment Details
Send RequestIf you do not see the specialty you are looking for, please call us at: 617-355-6000.International visitors should call International Health Services at +1-617-355-5209.
Please complete all required fields

This department is currently not accepting appointment requests online. Please call us at: 617-355-6000. International +1-617-355-6000.

This department is currently not accepting appointment requests online. Please call us at: 617-355-6000. International +1-617-355-6000.

Thank you.

Your request has been successfully submitted

You will be contacted within 1 business day.

If you have questions or would like more information, please call:

617-355-6000 +1-617-355-6000
Find a Doctor
Search by Clinician's Last Name or Specialty:
Select by Location:
Search by First Letter of Clinician's Last Name: *ABCDEFGHIJKLMNOPQRSTUVWXYZ
Condition & Treatments
Search for a Condition or Treatment:
View allSearch
The future of pediatrics will be forged by thinking differently, breaking paradigms and joining together in a shared vision of tackling the toughest challenges before us.”
- Sandra L. Fenwick, President and CEO