Cervical Assessment via Ultrasound Elastography: Calibrated Reference Material Development

The human cervix serves a dual structural function throughout pregnancy. Prior to term, the cervix remains closed and firm to support the increasing weight of the fetus. At term, it must soften ( i.e., ripen) and dilate to permit birth. Timing of cervical ripening is critical for pregnancy outcome. Cervical insufficiency, or preterm ripening, is diagnosed if a cervix is not stiff enough to support the pregnancy to term and may cause miscarriage or preterm labor. This is sometimes observed mid-pregnancy when funneling at the internal os or shortening of the cervix is observed during a routine ultrasound. Women with a shorter cervix are at a higher risk for spontaneous preterm delivery. ^1,2 While cervical length is not a definitive predictor of preterm delivery, a short cervix increases the risk. Moreover, the exact length at which the cervix is considered to be ‘short’ is poorly defined. While transvaginal B-mode ultrasound can identify a short cervix, this procedure is performed when clinically indicated. Cervical ripening and effacement is asymptomatic and thus is often missed until after a patient has suffered a second or third trimester miscarriage.