Donald School Journal of Ultrasound in Obstetrics and Gynecology

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VOLUME 15 , ISSUE 1 ( January-March, 2021 ) > List of Articles


Ultrasonographic Assessment of the Cervix for Prediction of Spontaneous Preterm Birth in Singleton Pregnancies

Zorán Belics, Zoltan Papp

Keywords : Digital examination, Perinatal morbidity, Perinatal mortality, Pregnancy, Prematurity, Transabdominal ultrasound, Transvaginal ultrasound

Citation Information : Belics Z, Papp Z. Ultrasonographic Assessment of the Cervix for Prediction of Spontaneous Preterm Birth in Singleton Pregnancies. Donald School J Ultrasound Obstet Gynecol 2021; 15 (1):49-63.

DOI: 10.5005/jp-journals-10009-1683

License: CC BY-NC 4.0

Published Online: 00-03-2021

Copyright Statement:  Copyright © 2021; Jaypee Brothers Medical Publishers (P) Ltd.


Spontaneous preterm birth remains a major cause of neonatal morbidity and mortality across the world. Hence, there is an urgent need to find and implement diagnostic methods and interventions that can reduce this public health treat. The ultrasonographic assessment of the cervix is one tool that can be utilized to identify women at increased risk who may be candidates for preventive interventions. There are three main characteristics of the cervix, which can be evaluated during the ultrasound examination of the cervix: cervical length (CL), funneling and cervical gland area. Cervical shortening is one of the first steps in the processes leading to labor and can precede labor by several weeks. Because shortening begins at the internal cervical os and progresses caudally, it is often detected on ultrasound examination before it can be appreciated on physical examination. This is equally true for funneling and cervical gland area (CGA), which cannot be assessed with the physical examination. Based on previous experiences, the timing and frequency of ultrasonographic assessment of the cervix is primarily based on the patient\'s prior obstetric history (low-risk women are screened once at 18–24 weeks of gestation; high-risk population usually begins screening at about 16 weeks of gestation and the frequency depends on the measurement result). Classically the diagnosis of short cervix is defined when the CL is less than or equal to 25 mm at these gestational weeks, with the best prediction for PTB obtained at 16–24 weeks of gestation. The CL measurement, evaluation of funneling and CGA together increased the sensitivity of cervical screening for PTB and appeared to be powerful predictor of PTB before 32 weeks gestation. Generally, the importance of positive test is to try to recognize cervical changes on time, to plane the adequate therapy, to prepare for sufficient intrauterine transport, and to administered course of antenatal corticosteroid therapy to women at risk for PTB reduced the incidence and severity of respiratory distress syndrome (RDS) and mortality in offspring. Many interventions (bed rest, lifestyle intervention, cervical cerclage, pessary, progesteron, indomethacin, antibiotics, etc.) have been proposed in an attempt to prevent PTB depending on risk classification.

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