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)
- multiple gestations
- obstetric/gynaecological trauma
- increase in prostaglandins 4
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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