Figure 2From: Elastography in predicting preterm delivery in asymptomatic, low-risk women: a prospective observational study Elastographic (left) and ultrasound (right) images of the internal cervical os (circles) at 18-22 weeks of pregnancy. Internal cervical os stiffness was assessed as: A) soft (red); B) medium soft (yellow); C) medium hard (blue); D) hard (purple).Back to article page