Shortening of the cervical canal

Dr Dan J Bell and Radswiki et al.

Shortening of the uterine cervical canal as the name implies refers to an abnormal shortening of the uterine cervical length. It is considered a sign of cervical incompetence in pregnancy and can lead to premature delivery.


  • primary (i.e. congenital/idiopathic)
  • secondary
    • multiple gestations
    • obstetric/gynaecological trauma
    • increase in prostaglandins 4

Radiographic features

In a single pregnancy the cervical length is usually considered to be ~4 cm up until 37 weeks, while in multifetal pregnancy it can often be <3 cm by 32 weeks 1

An endocervical canal length of <3 cm or <2.5 cm (depends on institution) is considered diagnostic of shortening 4,5.

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Article information

rID: 15284
Section: Signs
Synonyms or Alternate Spellings:
  • Short cervical length
  • Shortened uterine cervix
  • Uterine cervical shortening
  • Cervical shortening
  • Short cervix
  • Short uterine cervix
  • Short uterine cervical length

Cases and figures

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    Case 1
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