What Is a Cervical Scan?
A cervical scan is a transvaginal scan to measure the length of the cervix. It is recommended in women at high risk for preterm birth, including multiple pregnancies, those with a previous preterm birth, abnormalities of the uterus, or previous cervical surgery. This examination is usually carried out at the time of the anomaly scan but in women with risk of preterm birth, it may be necessary to perform a series of scans starting from 16 weeks gestation.
Do I need a cervical Length Screening?
Indications where we offer cervical length screening and preterm birth counselling
- You went into labour naturally and had your baby between 24+0 and 33+6 weeks gestation in a previous pregnancy
- You went into labour and had a late miscarriage between 16+0 and 23+6 weeks gestation
- Your waters broke between 16+0 and 33+6 weeks in a previous pregnancy (called preterm prelabour rupture of membranes [PPROM]).
- You have had previous surgery on your cervix such as a LLETZ (large loop excision of the transformation zone) or cone biopsy to remove abnormal cells in the cervix
- You have had a previous caesarean section in labour when you were fully dilated (your cervix was fully open)
- You had a cervical cerclage (stitch) in a previous pregnancy
- Previous trachelectomy for treatment of cervical cancer
- You have a variation in the size and shape of your uterus, e.g. bicornuate, unicornuate uterus, uterine septum
- You have adhesions (scar tissue) in your uterus sometimes known as Asherman’s syndrome
- Your current pregnancy is a high-risk pregnancy like Multiple Pregnancy
Why Is a Cervical Scan Performed During Pregnancy?
- For assessing the cervical length
- For evaluating cervical funnelling or incompetence
- For guiding treatment decisions
- Assessing placental position
How Is a Cervical Scan Performed?
Cervical scans are typically performed transvaginal (internal scan) because this method provides a more accurate measurement of the cervix compared to abdominal ultrasound.
