Ambiguous Genitalia

Ambiguous Genitalia

Deborah L. Jacobson

Elizabeth B. Yerkes


  • Clitoris

    • The corpora cavernosa (erectile bodies) of the clitoris originate proximally as paired crura, swell medially to form the clitoral bulbs, and unite distally.

    • The paired cavernosa support a glans covered by a prepuce of labia minora. MRI imaging studies performed by O’Connell et al demonstrate that the glans lies caudal to the corporal bodies, leading to a natural hairpin curve.1

    • Autonomic input is via the paired cavernous nerves, which originate from the vaginal plexus at the 10 and 2 o’clock positions along the vagina and course dorsally along the proximal urethra.2 The nerves travel with the cavernous arteries and enter the clitoral bodies under the pubic arch.

    • Somatic supply is via the paired dorsal nerves of the clitoris, which originate from the pudendal nerves, run dorsolaterally along the crura and ischiopubic rami at approximately the 11 and 1 o’clock positions, and enter the glans at the corona. The nerves branch, fanning out along the clitoral bodies dorsally and laterally. Nerves are absent in the dorsal midline and deficient ventrally.

    • The cavernous arteries originate from the internal pudendal artery, travel with the cavernous nerves, and enter the clitoral body under the pubic arch. Dissection between the crura at the pubic arch should be avoided.

    • Variations from typical clitoral anatomy should be expected in patients with virilization of female genital tissue.

  • Labia

    • The labia majora embryologically correspond to the male scrotum. They are separated by the vulvar cleft, which contains the labia minora and clitoris. Together the structures conceal the vestibule.

    • The labia minora and urethral plate correspond to the male anterior urethra. The labia join superiorly to frame the glans clitoris as the clitoral hood.

  • Vagina

    • The vagina consists of a rugated mucous membrane fixed to a bilayered muscular invagination. It is suspended from the levator ani ventrally, the rectovaginal septum dorsally, and the cervix apically.

    • Arterial supply is via uterine, vaginal, and internal pudendal branches coursing along the anterolateral surface of the vagina.

    • Innervation originates anterolaterally via autonomic branches of the uterovaginal plexus and somatic branches of the pudendal nerve.

    • The ureters pass adjacent to the lateral margins of the vagina and insert into the base of the urinary bladder.


  • Cloacal development

    • The cloacal membrane folds with differential embryonic growth beginning in week 4, and the cloaca partitioned into anterior (urogenital sinus—UG sinus) and posterior (hindgut) compartments with the descent of the urorectal septum.

    • Disruption of normal cloacal development can lead to persistent cloaca or UG sinus anomalies.

  • Development of the external genitalia

    • Fetal androgenization leads to elongation of the genital tubercle, fusion of the urethral folds, and fusion of the labioscrotal folds.

  • Development of the abdominal wall

    • Failure of mesodermal ingrowth or premature rupture of the cloacal membrane leads to bladder or cloacal exstrophy.

    • Development of the UG sinus

    • Caudal paramesonephric (Müllerian) duct deficiencies may lead to agenesis of the proximal vagina and variable anatomy of the uterus/fallopian tubes (Mayer-Rokitansky-Küster-Hauser syndrome).

    • Lateral paramesonephric (Müllerian) fusion anomalies may lead to uterus didelphys, bicornuate uterus, or unicornuate uterus.

    • Deficiency of the distal UG sinus may lead to vaginal atresia.

    • Incomplete vaginal canalization may lead to an imperforate hymen or transverse vaginal septum.


  • The natural history of an individual in this population, or the population as a whole, is not entirely known.

  • For androgenized individuals, it is unclear what the prenatal hormonal milieu (both in terms of absolute androgen levels and the response of developing genital/nervous tissues) portends for future gender identity or sexuality.

  • For virilized females (such as patients with congenital adrenal hyperplasia) in whom medical control is irregular, continued irreversible changes may occur in the genital tissues.

  • The psychosocial outcomes of early vs delayed surgery remain unclear, as does the definition and likelihood of surgical success.


  • Antenatal course: complications, history of prematurity, and other anomalies

  • Evidence of maternal exposure to endogenous or exogenous androgen

    • Severe acne, abnormal hair growth, clitoral enlargement, or Cushingoid appearance

    • Drugs, virilizing tumors, or adrenal disorders

  • Family history:

    • Known chromosomal anomalies

    • Fetal/neonatal demise

    • Genital ambiguity or urologic anomalies

    • Infertility or consanguinity

  • Physical examination

    • General: overall appearance, dysmorphic features, and general infant well-being

    • Spine: gross deformity or neurocutaneous marks

      • Anomalous findings may indicate genetic syndromes or fetal exposures.

      • Tethered cord or occult spinal cord anomalies are common with select diagnoses.

    • Abdomen: marked distention, hernias, suprapubic masses, and wall abnormalities

      • May indicate bladder outlet obstruction, hydrometrocolpos, or urinary ascites

    • Perineum

      • Labioscrotal folds: prominence, rugation, pigmentation, and presence of gonads

      • Clitorophallic structure: dorsal stretched length, glans width, and corporal consistency

      • Perineal orifices: number, location, and patency

      • Gonads: presence by palpation, location, and consistency

        • Palpable gonadal tissue suggests presence of at least some ipsilateral testicular tissue


  • Create a multidisciplinary team incorporating experienced pediatric urologists/pediatric surgeons/pediatric gynecologists, endocrinologists, psychiatrists/psychologists, geneticists, and nurses/social support members to work with the parents and child to guide patient care. Consider formal ethics consultations when appropriate.

    • There is a broad spectrum of “normal” female external genitalia. Referring providers, parents, and patients may be reassured by education on range of “normal.” Appearance and future functionality are important to consider in the pediatric patient if surgery is requested.

    • The timing and indications for feminizing genital reconstruction are currently controversial, and there may be long-term consequences of both action and inaction in this arena.

    • Performing feminizing surgery in prepubertal children precludes autonomous self-determination in surgical decision-making and may lead to regret.

  • Consider the psychosocial consequences of genital ambiguity, and provide appropriate counseling for patient and parent.

    • Patients deserve long-term psychological support, with or without surgical intervention.

    • Extended support networks may be found both within the hospital and in the patient’s own community.

  • Discuss patient reproductive potential, optimizing patient sexual development and fertility when possible. Administration of androgens or estrogens may be recommended in longer term, depending on the underlying anatomy and function.

  • Consider the potential for gonadal malignancy, which varies significantly with gonadal histology and patient pathophysiology. Whenever possible, gonadal preservation should be considered.


Preoperative Planning

  • Diagnostic laboratory evaluation may include karyotype, serum electrolytes, 17-hydroxyprogesterone, testosterone, luteinizing hormone, and follicle-stimulating hormone levels. Additional adrenal and sex hormone testing is used more selectively but is essential to make a diagnosis in some cases.

  • A thorough examination under anesthesia should be completed, including inspection of external genitalia, palpation for gonads, cystoscopy, vaginoscopy (if applicable), and genitography.

  • Consider the need for gonadal biopsy or gonadectomy at the time of intervention, along with possible gonad cryopreservation.

  • Patients undergoing vaginoplasty require bowel preparation (enema vs polyethylene glycol solution) prior to surgical intervention.


  • Isolated genitoplasty with or without repair of a low UG sinus is generally performed in frog-leg (infants, young children) or dorsal lithotomy (older patients) position with padding of all pressure points.

  • For reconstruction of a high UG sinus, most patients will require both prone and supine positioning, so total lower body preparation is utilized. This preparation may be advantageous in infants and young children for sterility of the field, whether high or low confluence.

    • Ensure there are no IVs in lower extremities.

    • A single-shot caudal block is reasonable in eligible patients, but a continuous caudal catheter is not utilized intraoperatively.

    • After endoscopy and catheter placement, keep the catheters sterile and move the patient up the table for second prep. Prep the lower body circumferentially from the xiphoid to the toes.

    • Place feet and legs in a stockinette.

    • Drape to allow for lower body repositioning from supine to prone within the drape (FIG 1).

    • Position the patient with stacked towels under the pelvis. Initial prone vs supine positioning will depend upon the planned procedures.


  • Primary components of the feminizing genitoplasty include the following:

    • Clitoral degloving

    • Elevation of the urethral plate and mobilization of the common UG sinus

    • Clitoral reduction

    • Urogenital sinus reconstruction and vaginoplasty

    • Creation of a clitoral hood and labioplasty

      FIG 1 • Prone view of circumferential body preparation from the xyphoid to the toes. The child is toweled out and “passed through” a drape to allow transitions from supine to prone within the drape. The hips will be elevated on stacked towels.

  • Several clitoral reduction techniques are utilized in contemporary feminizing genitoplasty.

    • Each is performed with attention to clitoral nerve sparing.

  • The timing of reconstruction elements is controversial.

    • “Early” single-stage reconstruction of the genitalia and UG sinus is performed with the goal of no additional procedures and no memory of the recovery. Additionally, the excess UG sinus tissue and genital skin can be redistributed as needed if the procedure is completed in a single stage. Despite these potential advantages, the smaller caliber of the infant vagina may increase the risk of vaginal stenosis and the likelihood of secondary procedures. Routine postoperative vaginal dilations are not recommended in this age group.

    • “Late” reconstruction preserves autonomous self-determination and allows the full advantage of virgin planes and tissues.

      • There may be limited options for positioning older patients.

      • Vaginal dilations will be required postoperatively, whether by medical grade dilators or sexual activity, so emotional maturity and commitment to outcomes are essential.

    • A staged reconstruction, by deferring either genitoplasty or vaginoplasty, precommits to two operative events and limits the redistribution of healthy tissues. The second stage may involve previously operated tissues.

  • The operative approach varies based on:

    • The surgical components to be included

    • The level of vaginal confluence in the UG sinus (“high” vs “low”)

    • The degree of virilization

Feb 27, 2020 | Posted by in Pediatric plastic surgery | Comments Off on Ambiguous Genitalia

Full access? Get Clinical Tree

Get Clinical Tree app for offline access