CME Review ArticleSonography and Transfundal Pressure in the Evaluation of the Cervix During PregnancyGuzman, Edwin R.; Houlihan, Christopher; Vintzileos, AnthonyAuthor Information Division of Maternal-fetal Medicine, Department of Obstetrics and Gynecology and Reproductive Sciences, University of Medicine and Dentistry-Robert Wood Johnson Medical School, St. Peter's Medical Center, New Brunswick, New Jersey. Reprint requests to: Edwin R. Guzman, MD, Division of Maternal-Fetal Medicine, St. Peter's Medical Center, MOB 4th Floor, 254 Easton Avenue, New Brunswick, NJ 08903-0591. Authors whose names are accompanied by an asterisk (*) have indicated, in accordance with the Accreditation Council for Continuing Medical Education (ACCME) Standards, that they have a relationship which could be perceived by some people as a real or apparent conflict of interest, but do not feel it has influenced their participation. Obstetrical & Gynecological Survey: May 1995 - Volume 50 - Issue 5 - p 395-403 Buy Abstract Ultrasonographic evaluation of the cervix in pregnancy has provided some insight into premature delivery and pregnancy wastage. Its use has led to the development of cervical length nomograms in uncomplicated singleton pregnancies and to the realization that varying degrees of cervical incompetence exist. In some instances the internal os has been observed to dilate and funnel in the early second trimester while in others these changes occur gradually into the third trimester. Transient cervical changes have been linked to premature delivery and extended ultrasonographic inspection is required for their detection. Although sonography may allow the identification of women who deliver prematurely, it has not demonstrated enough discriminatory power to recommend its routine use for this purpose. Pre- and postoperative inspection of the cervix in elective and emergency cerclage procedures may become influential in outpatient management. A method of functional evaluation of the cervix using transfundal pressure (TFP) has been introduced which may lead to earlier diagnosis of cervical incompetence. The significance of descent of the membranes in response to TFP and sonographic findings consistent with premature cervical changes have not been validated because of surgical intervention performed in response to these findings. Our review concludes that, although sonography of the cervix may be useful in selective cases, more information on the natural history of abnormal cervical sonographic findings and controlled randomized trials are needed before recommendations on surgical intervention can be made. © Williams & Wilkins 1995. All Rights Reserved.