Research has shown that the shorter a woman’s cervix is, the higher the chance that her baby will be born prematurely. A preterm delivery is where baby is born after 24 weeks, but before the 37th week of pregnancy, but as you can imagine the outcomes for babies born at 24 compared to 36 weeks are very different. Most babies delivered after 34 weeks will do very well with our fantastic neonatal doctors. However, babies delivered before 34 weeks and especially before 28 weeks tend to do less well, irrespective of all the care and expertise that the baby doctors can give.
A cervical length scan is a transvaginal (internal) scan to measure the length of the cervix (“neck of the womb”). This scan is strongly recommended to women who are more likely to have a preterm birth, including those who have previously had a baby early, have had surgery on their cervix or have an unusually shaped uterus. It can also be safely performed on anyone without these histories. In the case the cervix is found to be short, different treatment options will be discussed to minimize the likelihood of preterm labour.
This examination is usually carried out at the time of the anomaly scan but it can be done separately anytime between 16 and 24 weeks of pregnancy.