Ambiguous Genitals
A birth defect where the outer genitals do not have the typical
appearance of either sex.
The genetic sex of a child is determined at conception. The mother's
ovum (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
a single pair of sex chromosomes -- one X from the mother and one
X or one Y from the father. Thus, the father is the one who "determines" the
genetic sex of the child. A baby who inherits the X chromosome
from the father is genetically a female (two X chromosomes). A
baby who inherits the Y chromosome from the father is genetically
a 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.
Ambiguous genitalia are those in which it is 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 (e.g., a genetic male may have
developed the appearance of a normal female).
Typically, ambiguous genitalia in genetic females (babies with
two X chromosomes) include an enlarged clitoris that has the appearance
of 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, resembling 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 (one X and one Y chromosome), ambiguous genitalia
typically include a small penis (less than 2-3 centimeters or 0.8-1.2
inches) that may appear to be 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;
it can be placed as low as on the peritoneum, further making the
infant appear to be female. There may be a small scrotum with any
degree of separation, resembling labia. Undescended testicles commonly
accompany ambiguous genitalia.
Ambiguous genitalia is usually not life threatening,
but can create social upheaval 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.
Common Causes of Ambigous Genitalia
Pseudohermaphroditism -- the genitalia
are of one sex, but some physical characteristics of the other
sex are present.
- True hermaphrodism -- very rare -- both ovarian and testicular
tissue is present and the child may have parts of both male
and female genitalia.
- Mixed gonadal dysgenesis -- some cells
in the body have only
a single X chromosome (female) and some cells in the body have
XY
chromosomes (male). This syndrome is variable, and depends
on which cells are female, which cells are male, and what percent
of each
there are.
- Congenital adrenal hyperplasia -- has several forms,
but the most common form causes the genetic female to appear
male.
Male infants
with the most common form appear normal at birth, but may
show premature sexual development as early as 6 months of age.
Many
states test for this as part of the newborn screen (the blood
test your baby has at 24-48 hours of life) because CAH can
be life-threatening.
chromosomal abnormalities, including:
- Klinefelter's syndrome (XXY) -- male,
usually has small testes; causes infertility; may be associated
with learning defects
or mental retardation; affects 1/500-1/1000 live male births)
- Turner's syndrome (XO) -- female; usually does not cause ambiguous
genitalia (usually looks female at birth), but
may have webbed
neck, swelling of the hands and feet and other characteristic
physical findings at birth; may not be diagnosed until
later in life when
sexual maturation does not take place; infertile)
- Maternal
ingestion of certain medications (particularly androgenic steroids)
-- may make a genetic female look
more male
Lack of production of specific hormones, causing the
embryo to develop with a female body type regardless
of genetic
sex
- Lack of testosterone cellular receptors (so even
if the body makes the hormones needed to develop into
a physical
male,
the body is
unable to respond to those hormones, and therefore,
a female body-type is the result even if the genetic
sex
is male)
Home Care
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.
Call your health care provider if:
- You are concerned about the
appearance of your child's external genitalia.
- Your baby takes
more than 2 weeks to regain his/her birthweight, is vomiting,
looks dehydrated (dry inside of mouth, no tears
when crying, less than 4 wet diapers per 24 hours, eyes look
sunken
in), has decreased appetite, has blue spells, or has trouble
breathing (these can all be signs of congenital adrenal hyperplasia).
- Ambiguous genitalia may be discovered during the first well-baby
examination.
What to expect at your health care provider's office
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, such as:
- family history questions to help identify
inherited chromosomal disorders
- 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 (see the Common Causes section)?
medications
- What medications has the mother taken before or during
pregnancy (especially steroids)?
other
- What other symptoms or abnormalities are also present?
DIAGNOSTIC TESTS
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, or 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.
TREATMENT
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. |
