Cervix appears as a soft tissue structure with medium-level echoes
Endocervical canal appears as echogenic line (mucus plug) surrounded by hypoechoic zone of endocervical glands
Cervical length: Normal cervix is >3 centimeters in length (length of endocervical canal from the internal os to the external os)
Cervical width: Anteroposterior (AP) diameter of the cervix at the midpoint between internal and external os
Gradual cervical effacement and shortening normally begins at ~30 weeks of gestation.
In multifetal pregnancy, cervix is much shorter from 20-week gestation onward.
Widening of os and cervical length <2.5 centimeters at </= 24 weeks is s/o cervical insufficiency.
• Funneling of the internal os has been reported as an early sign (Figure 28.1).
Seen as a bulging/herniation of fetal membranes >3 millimeters into the internal os.
>50% funneling before 25 weeks is a/w >75% risk of preterm delivery.
• Shortening of cervical canal (from internal os to external os).
• Cervical canal gets dilated and in severe cases, amniotic sac may prolapse through (Figure 28.2) the cervix into vagina with or without the products of conception. (Bulging amnion).
Figure 28.1 Illustrating incompetent cervix.
Related posts:
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
