Comparison of ultrasonic measurements of nulliparous versus multiparous cervices

Premature remodeling of uterine cervical microstructure plays a large role in preterm birth. Invasive studies confirm that collagen, the major contributor to cervical strength, undergoes rearrangement long before changes associated with pre-delivery remodeling (shortening, softening, dilation) are grossly detectable. However, a lack of noninvasive technology sophisticated enough to interrogate the cervical microstructure makes quantitative assessment of the cervix challenging. Therefore, clinical cervical assessment is subjective. For instance, clinicians can feel a difference in softness between a nulliparous (never had babies) and multiparous (had babies) cervix. Further, they become concerned about preterm birth risk when the cervix feels “too soft” in midgestation. The inability to objectively describe these parameters impedes clinical management; in other words, currently there is no means to answer critical questions such as “how soft is too soft?”. Our preliminary results using quantitative ultrasound (QUS) techniques and shear wave sound speeds (SWS) to objectively describe cervical microstructure and softening suggest that these measurements are sensitive enough to detect differences between the nonpregnant nulliparous and multiparous cervix, and thus are promising for quantitative assessment of the cervix in pregnancy.