Transvaginal Sonographic Evaluation of the Cervix in Asymptomatic Singleton Pregnancy and Management Options in Short Cervix

Resul Arisoy,Murat Yayla

doi:10.1155/2012/201628

Abstract

Preterm delivery (PTD), defined as birth before 37 completed weeks of gestation, is the leading cause of perinatal morbidity and mortality. Evaluation of the cervical morphology and biometry with transvaginal ultrasonography at 16–24 weeks of gestation is a useful tool to predict the risk of preterm birth in low- and high-risk singleton pregnancies. For instance, a sonographic cervical length (CL) > 30 mm and present cervical gland area have a 96-97% negative predictive value for preterm delivery at <37 weeks. Available evidence supports the use of progesterone to women with cervical length ≤25 mm, irrespective of other risk factors. In women with prior spontaneous PTD with asymptomatic cervical shortening (CL ≤ 25 mm), prophylactic cerclage procedure must be performed and weekly to every two weeks follow-up is essential. This article reviews the evidence in support of the clinical introduction of transvaginal sonography for both the prediction and management of spontaneous preterm labour.

Highlights

Preterm delivery occurs in 5–13% of pregnancies before 37 weeks’ gestation
While hospital tocodynamometry has been effective for monitoring uterine contractions to evaluate preterm labor, home uterine activity monitoring (HUAM) has not been proven valuable in detecting or preventing preterm birth and is not currently recommended for use [17, 18]
Paternoster et al assessed phIGFBP-1 in cervical secretions and the sonographic measurement of cervical length in 210 symptomatic patients. They found that 26 mm was the best cut-off value for cervical length in terms of predicting preterm delivery (LR+, 3.69; LR−, 0.22), with a sensitivity of 86.4%, specificity of 71.9%, positive predictive value (PPV) of 34.5%, and negative predicting value (NPV) of 96.8%

Summary

Introduction

Preterm delivery occurs in 5–13% of pregnancies before 37 weeks’ gestation. Preterm delivery is a major cause of perinatal morbidity and mortality [1,2,3,4,5,6,7]. The exact mechanism of preterm labor is largely unknown but is believed to include decidual hemorrhage (e.g., abruption, mechanical factors such as uterine overdistension from multiple gestation or polyhydramnios), cervical incompetence (e.g., cone biopsy), mullerian duct abnormalities, fibroid uterus, cervical inflammation (e.g., resulting from bacterial vaginosis, trichomonas), maternal inflammation and fever (e.g., urinary tract infection), hormonal changes (e.g., mediated by maternal or fetal stress), and uteroplacental insufficiency (e.g., hypertension, insulin-dependent diabetes, drug abuse, smoking, alcohol consumption) Each of these underlying causes can initiate the cascade of events that lead to uterine activity and cervical dilation. While hospital tocodynamometry has been effective for monitoring uterine contractions to evaluate preterm labor, home uterine activity monitoring (HUAM) has not been proven valuable in detecting or preventing preterm birth and is not currently recommended for use [17, 18]

Biomarkers of Preterm Birth

Cervical Assessment by Ultrasonography

The Cervical Morphology and Biometry for the Prediction of Preterm Birth

Findings

Management Options for Short Cervix