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Articles » Genital anomalies » Labial fusion

2005-04-21-13 Labial fusion © Jeanty

Labial fusion

Chaitali Shah, MD, Philippe Jeanty, MD, PhD, Ashok Bhanushali, MD

Tennessee Women"s Care, Nashville, TN


Synonyms: Labial adhesion, female phimosis, urocolpos, synechia vulvae

Definition: Adhesion or fusion of the labia is a common benign gynecologic disorder in the pediatric population 1 and is defined as partial or complete adherence of the labia minora or majora. It is usually a midline fusion and maybe visible as a thin translucent streak. This disorder is usually asymptomatic and may first be noticed due to repeated urinary tract infections.

Case report:  This is a woman who presented for a routine ultrasound scan and the following images were obtained. They demonstrate a duplication of the collecting system but mostly a perineal cystic collection that is NOT the bladder but communicates with the bladder:


The following is a video-clip demonstrating the passage of urine from the bladder into the cystic mass and what appeared to be labia majora fused over the "cyst":

The ultrasound findings suggest the presence of a cystic structure seen close to but external to the introitus. This was likely to be external to the hymen so it did not appear to represent a hydrocolpos. This was essentially a urinoma that developed due to fusion of labial folds leading to obstruction of the urinary flow. Since the amniotic fluid was normal we assumed there must have been a slow leak although we could not demonstrate it.

The following is a postnatal photograph of the female neonate, demonstrating the fused labia majora. They were surgically separated and the introitus and the rest of the baby was normal (aside for the duplication of the collecting system of course)

Prevalence: According to the data in the published literature, labial adhesion is occasionally seen in the newborn period. The age at which this disorder is commonly seen ranges from 13-23 months with an incidence of 1.8%. 2,3 It is sometimes seen in women of reproductive age group as well and more commonly in postmenopausal women. 4 

Etiopathogenesis: Labial adhesions may be congenital as in this case or a complication of:

  • Exposure to drugs such as chlorpyrifos [Dursban] and danazol. 6,7
  • Adrenal steroid 21-hydroxylase deficiency 8

Postnatally, they may also result from inflammation that occurs secondary to various causes and resultant scarring, estrogen deficiency and lack of sexual activity. 5 Numerous causes have been cited for this, a few of these are:

  • Hypo-estrogenic states as in pre- and postmenopausal women predispose them to developing labial adhesions.
  • Local causes such as disabling hip problems that interfere with perineal hygiene and sexual activity.
  • Labial fusion may be the presenting feature of genital lichen sclerosus 9

Sonographic findings: Labial adhesions can be adhesions of the labia minora or of the majora. The labia minora adhesions are a more common occurrence and more easily rectifiable. These adhesions are usually recognized easily by physical examination. However the affected individuals might be sent for a scan due to repeated urinary tract infections. Ultrasound does not usually reveal anything except, if there is a urinary collection [a urinoma] that might have occurred due to the pinhole sized meatus and resultant poor stream of urine. This is also the basis of antenatal diagnosis of this condition.

In one study, where voiding cystourethrography was performed in children with urinary tract infections, the radiologist was the initial person involved in making this diagnosis by observing collection of contrast material above the labia and marked reflux into the vagina. 11


Complications: repeated urinart tract infections, bladder distention and hydronephrosis due to urinary outflow obstruction

Prognosis: This disorder follows a benign course and has good prognosis. 

Management: Topical estrogen cremes usually are sufficient to treat labia minora adhesions. Labia majora adhesions and dense fibrous adhesions may need adhesiolysis and corrective surgery. 12   

1. Alagiri Madhu. Labial Adhesions.
2. K. Radhakrishna, B. Rajasekhar. Labial fusion. Indian Pediatrics 2002; 39:783-784
3. Leung AK, Robson WL, Tay-Uyboco J. The incidence of labial fusion in children. J Paediatr Child Health. 1993 Jun;29(3):235-6.
4. Uei T, Katou Y, Shimizu N, Yamanaka H, Seki M, Ibuki R. Labial adhesion in a reproductive woman with difficulties of sexual intercourse and urination: a case report. Hinyokika Kiyo. 2000 Jun;46(6):433-6.
5. Inoue K, Ohmori K, Kyuma M. A case of labial adhesions with urinary retention. Hinyokika Kiyo. 1996 May;42(5):393-395.
6. Sherman JD. Chlorpyrifos (Dursban)-associated birth defects: report of four cases. Arch Environ Health. 1996 Jan-Feb;51(1):5-8.
7. Brunskill PJ. The effects of fetal exposure to danazol. Br J Obstet Gynaecol. 1992 Mar;99(3):212-5.
8. Karaviti LP, Mercado AB, Mercado MB, Speiser PW, Buegeleisen M, Crawford C, Antonian L, White PC, New MI. Prenatal diagnosis/treatment in families at risk for infants with steroid 21-hydroxylase deficiency (congenital adrenal hyperplasia). J Steroid Biochem Mol Biol. 1992 Mar; 41(3-8):445-51.
9. Gibbon KL, Bewley AP, Salisbury JA. Labial fusion in children: a presenting feature of genital lichen sclerosus? Pediatr Dermatol. 1999 Sep-Oct;16(5):388-91.
10. Leung AK, Robson WL. Labial fusion and urinary tract infection. Child Nephrol Urol. 1992;12(1):62-4.
11. Ben-Ami T, Boichis H, Hertz M. Fused labia. Clinical and radiological findings. Pediatr Radiol. 1978 Apr 10;7(1):33-5.
12. Muram D. Treatment of prepubertal girls with labial adhesions. J Pediatr Adolesc Gynecol. 1999 May;12(2):67-70.

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