Bladder, ureter & renal pelvis

Congenital anomalies

Persistent cloaca

Last author update: 1 April 2011
Last staff update: 23 November 2020

Copyright: 2003-2023,, Inc.

PubMed Search: Persistent cloaca

Alcides Chaux, M.D.
Page views in 2022: 376
Page views in 2023 to date: 291
Cite this page: Chaux A. Persistent cloaca. website. Accessed October 4th, 2023.
Definition / general
  • Defined as confluence of rectum, vagina and urethra into a single common chamber that opens into a single orifice where the normal urethral opening is located
  • Represents a wide spectrum of defects with the common denominator of a single perineal orifice
  • The length of the common chamber varies from 1-10 cm (average 3 cm)
  • Also called cloacogenic bladder
  • Occurs in 1 per 20,000 births, only in girls
  • Cloaca is single canal from which the urinary, genital and intestinal tracts arise at gestational weeks 5-6
  • Persistent cloaca is due to failure of urogenital septum to divide rectum from urogenital sinus
  • May be related to B-class Eph/ephrin signaling (J Pediatr Urol 2007;3:354)
Diagrams / tables

Images hosted on other servers:

Normal embryo at 25 - 27 days

Normal embryo at weeks 5 - 7

Diagram of persistent cloaca

Clinical features
  • Dilated sac like structure in center of abdomen
  • 80% have an associated anogenital anomaly, including imperforate anus, absent genital or urinary orifices, renal agenesis, absence of prostate or seminal vesicles or poorly developed foregut derivatives
  • 30% of patients present with hydrocolpos (dilated vagina filled with fluid, urine or mucus) and 40% have a duplicated Müllerian system
  • May be identified prenatally by ultrasound or MRI in a female fetus presenting with hydronephrosis and a large cystic lesion arising from the pelvis (Congenit Anom (Kyoto) 2009;49:116)
Case reports
Additional references
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