A comparison of ultrasonographically detected cervical changes in response to transfundal pressure, coughing, and standing in predicting cervical incompetence.

Objective: Our purpose was to compare various noninvasive stress techniques for their ability to elicit ultrasonographic cervical changes and to determine their efficacy in detecting ultrasonographic cervical incompetence.

Study Design: Eighty-nine patients at risk for pregnancy loss and preterm birth underwent ultrasonographic evaluation of the cervix at least twice between 15 and 24 weeks of gestation. With use of a transvaginal probe, the funnel width, funnel length, and endocervical canal length were measured in millimeters with the patient in the supine position.