Anorectal Malformations (ARM)

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A prospective, national observational study to determine the incidence, presentation, investigation and current management strategies of anorectal malformation in the UK and Ireland.

Key Points

  • Contemporary information about the incidence of live-born infants with ARM is limited.
  • It is acknowledged that many patients with these abnormalities present late.
  • Variation in practice exists in both intra-operative and peri-operative management for patients with the same malformation.
  • Outcomes of different modes of treatment are unclear.
  • This study will provide a national picture of the incidence of newly diagnosed cases of anorectal malformation, its associated abnormalities, management and outcomes.

Surveillance Period

1st October 2015 – 30th September 2016


Anorectal malformation is said to have an incidence of about 1 in 5,000 live births[1].  This term describes a spectrum of anomalies which may occur in isolation or associated with other congenital malformations such is seen in the VACTREL association and in other syndromes such as Trisomy 21[2].  Such patients’ treatment is individualised according to their burden of comorbidity.

Attempts have been made in the international paediatric surgical community to standardise the classification of anatomical variations seen in these patients[3].  Variation in surgical practice exists in the way patients with the same abnormality are treated. Outcome data on complication rates and long-term function are largely limited to single institution series.


To estimate the diagnosed incidence and birth incidence of anorectal malformation in the UK and Ireland, assess their burden of comorbidities and describe their management and outcomes to 28 days and one year post-operatively.

Research Questions

  • What is the current incidence of new cases of anorectal malformation in the UK and Ireland?
  • How many patients present late (defined as having a diagnosis after the first 24 hours of life)?
  • How are patients with anorectal malformation managed?
  • What is the incidence of associated abnormalities in these patients?
  • What are the adjusted outcomes for infants managed with the same abnormality managed with different surgical techniques eg. primary vs staged repair, method of reconstruction in patients with perineal fistula?
  • What factors are important in prognostication?

Case Definition

All children in the UK with imperforate anus or absence or narrowing of the communication canal between the rectum and anus with or without fistula to neighbouring organs, newly diagnosed during the study period, irrespective of age at presentation or any additional anomalies.

Ethics Approval

The study has been approved by the NRES Committee South Central-Oxford A (Ref: 12/SC/0416).

Study Team

Paulo Di Coppi, Consultant Paediatric Surgeon, Great Ormond St Hospital; Thanos Tyraskis, Academic Clinical Fellow, London Deanery; Anna-May Long, Clinical Research Fellow in Paediatric Surgery, NPEU; Marian Knight, Professor of Maternal and Child Population Health, NPEU.

Download the Data Collection Form (DCF)

BAPS-CASS Anorectal Malformation DCF


  1. ^ Coran, A.G., N.S. Adzick, and J.L. Grosfeld, Pediatric surgery. 7th ed. 2012, Philadelphia, PA: Elsevier Saunders.
  2. ^ Pinsky, L., The syndromology of anorectal malformation (atresia, stenosis, ectopia). Am J Med Genet, 1978. 1(4): p. 461-74.
  3. ^ Holschneider, A., et al., Preliminary report on the International Conference for the Development of Standards for the Treatment of Anorectal Malformations. J Pediatr Surg, 2005. 40(10): p. 1521-6.

Updated: Monday, 06 July 2020 17:08 (v8)