Measuring the Cervical Length.

An important step toward the goal of eradicating spontaneous preterm birth was achieved with the advent of cervical sonography, a tool that advanced our knowledge of the entity of preterm parturition, improved our ability to detect women at risk for early delivery, and allowed us to prevent some of these premature births. We will describe here the correct technique for obtaining such measurements and will review the literature regarding the use of this tool in specific pregnant populations.