Abstract
Transvaginal sonography of the cervix has emerged as a useful window into preterm parturition. Cervical sonography allows measurements of cervical length (CL), which can aid clinicians in identifying women at risk for preterm birth. The use of transvaginal assessments of CL can assist in the triage of patients with possible preterm labor. Recent studies also support the use of CL measurements as a means of determining appropriate candidates for cerclage placement and progesterone supplementation to reduce the risk of premature birth, further highlighting the importance of this modality in modern obstetric management.