is cervical length measured in cm
In obsteric and gynaecological imaging, the cervical length (CL) is defined as the length between the internal cervical os and the external cervical os. the cervical length is most accurately assessed on a transvaginal scan with an empty bladder. in a normal gravid situation the cervical length is considered to be at least 30 mm (3 cm) the presence of a full bladder can increase the cervical length particularly on a trans-abdominal scan.
Cervical length. The length of the cervix is the distance between the internal os and the external os. First-trimester cervical length is greater than 5 cm. The cervical length decrease to less than 34 mm at 28 weeks' gestation. In patients who have had multiple gestations, the cervix is notably shortened.