Ambiguous GenitaliaWhen a child is born with ambiguous genitalia (external genitals that are not clearly male or female) it is essential that prompt diagnosis and gender assignment be made. The infant born with ambiguous genitalia will have tests done to determine the genetic gender. One of these is a blood test that determines the infant's karyotype. Normally, male infants have a 46 XY karyotype while females have a 46 XX karyotype. Regardless of the final results of the karyotype, families need to know the infant's gender. When it is unclear at birth, the infant is usually given a female gender assignment. This is related to the much more successful reconstructive surgery of female external genitalia. Among surgeons world wide, it is uniformly agreed that an adequate penis cannot be successfully constructed. Thus over the long term, the well being of both child and family are better served when the child is given the female gender role. The only exception to this is the genetic male with severe penoscrotal hypospadius and bilateral undescended testes, who is always reared as a male. There are four major pathological groups of patients with ambiguous genitalia: congenital adrenal hyperplasia, mixed gonadal dysgenesis, testicular feminization syndrome, and true hermaphroditism. Each of these is described below along with surgical options. Infants born with congenital adrenal hyperplasia (CAH) are genetic females (46XX) who have been exposed to high levels of male hormones in the uterus. The increased levels of male hormones are a result of an enzyme deficiency. Long term exposure to these male hormones effects the development of the infant's external genitalia. Infants that have had this long term exposure have external genitalia that range from mild clitoral enlargement to complete masculinization of the urethra with a normal appearing penis. All of these children are female and have normal fertility. Therefore the goal of surgery is to open or enlarge the vagina and cosmectically alter the clitoris. Surgery is usually performed between 3 to 6 months of age. If the child's anatomy is more complex, surgical intervention is sometimes delayed until two or more years of age. Mixed gonadal dysgenesis is a condition in which the infant has both male and female components. Thus the infant can have both ovaries and testes. The karyotype of these children is a mixture of 45 XO and 46 XY. The medical term for ovaries and testes is gonads. In children with mixed gonadal dysgenesis, the ovaries and testes function abnormally. Approximately 50% of children with mixed gonadal dysgenesis develop malignant tumors in dysgenetic gonads. For this reason surgical removal of the gonads is recommended. Surgical reconstruction is the same as infants with CAH. All these patients should be raised as females and undergo appropriate reconstruction of the external genitalia. Infants born with testicular feminization syndrome are genetic males (46XY) with external genitalia appearing more female. This is caused by inadequate levels of testosterone, inability of the target organs to convert and use the testosterone, or deficiencies in the number of receptors for the hormones. These children are raised as females because in every case the penis is inadequate for the male gender role. Occasionally this diagnosis is only made when a child believed to be female presents for inguinal hernia repair and during the surgery testes are discovered rather than ovaries. In this case, the testes are removed at the time of hernia repair rather than waiting until the age of puberty. If no other surgery is planned, removal of the testes should be done just before puberty to prevent male development during puberty. All of these children have a very short vagina, however most can be treated with vaginal dilation and will have a functionally adequate vaginal cavity at maturity. If the vagina is too small and cannot be dilated adequately the child may require vaginal replacement. This is done surgically utilizing a small section of colon to create a vagina. If the child's clitoris is enlarged, it is also surgically reduced to improve the female appearance of the genitalia. True hermaphrodites are the rarest form of ambiguous genitalia. These children have both normal male and female gonads with an ovary on one side and a testis on the other or an ovotestis, a gonad which has both male and female components, on one or both sides. Eighty percent are genetically female (46XX), although external genitalia may appear more male. Most have an inadequate penis and should be raised as females. In these children, the testis or testicular portion of the ovotestis should be removed leaving ovaries or female structures in place. Surgical reconstruction is similar to that used for the child with CAH or MGD. If the penis is adequate for the male gender role, then all ovarian and female structures are removed and a hypospadius or penile repair is carried out. Just after puberty, testicular prostheses are inserted into the scrotum to improve the male appearance. In all cases of ambiguous genitalia, the timing of the surgical procedure represents a balance between the psychological advantages of early surgery and the technical limitations imposed by the small size of the child's anatomy. The trend is clearly toward earlier reconstruction when appropriate. However, high insertion of the vagina into the urinary tract is an indication for postponing surgery until two years of age. Determination of the exact location of the insertion of the vagina into the genitourinary system is best done with an x-ray study called a retrograde genitogram. The study is not painful for the child and provides the surgeon with valuable information needed for planning the surgery. Endoscopy is also done at the time of surgery. Vaginoplasty, or reconstruction of the vagina, can be performed in the newborn period if the communication between the vagina and the urethra is beyond the external sphincter of the urethra. The external sphincter is the muscle allowing control of the flow of urine. If the communication is at or above the sphincter, then a vaginal pull-through, or more complex reconstruction, is the appropriate operation and should be done in the older child to decrease the incidence of postoperative vaginal stenosis or scarring. Clitoral resection is no longer recommended. The importance of the clitoris for orgasm and normal sexual function in known and all attempts to preserve all or part of the clitoris with its nerve supply should be made. The preferred operation is clitoral recession in which the clitoris is recessed or pulled back under the pubic bone. This procedure gives an excellent cosmetic result and the clitoris is left intact. The long-term functional results are not yet known because most of the patients who have undergone this procedure have not yet reached sexual maturity. Taking care of children with ambiguous genitalia continues to be one of the more challenging diagnostic as well as therapeutic problems facing the pediatric surgeon. The treatment of these children underscores the importance of a multidisciplinary approach involving pediatric endocrinology, neonatology, and pediatric surgery. Because ambiguous genitalia is such a rare problem, a large experience is needed in order to properly care for and recognize the variations and complexities seen. Suggested readings authored by the University of Michigan, Section of Pediatric Surgery
This information is provided by the University of Michigan Department of Surgery, Section of Pediatric Surgery and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional health information, please contact your health care provider or our offices. |
