title: Precocious cervical ripening as a screening target to predict spontaneous preterm delivery among asymptomatic singleton pregnancies: a systematic review.
abstract: Routine second-trimester transvaginal ultrasonographic (TVU) screening for short cervical length (CL) predicts spontaneous preterm delivery (SPTD), albeit with limited sensitivity (35-40%) and a moderate positive likelihood ratio of 4-6. However, CL describes one of the multidimensional changes that are associated with precocious cervical ripening (PCCR) and that also include cervical softening, cervical funneling (CF), and dilation. PCCR, a precursor and a strong predictor for SPTD, was proposed as a potential screening target. We hypothesized that screening for composite measures of PCCR (eg, CL, CF, cervical consistency, and dilation) with the use of either digital examination or TVU would improve the prediction of SPTD compared with screening for short CL alone. We searched PubMed and EMBASE electronic databases for observational cohort studies to evaluate cervical screening in asymptomatic obstetric populations. Multidimensional composite cervical measures were assessed in 10 datasets (n = 22,050 pregnancies) and 12 publications. Appreciable heterogeneity in cervical measurements, data quality, and outcomes across studies prevented quantitative metaanalysis. Only one study reported intra- and interobserver reliability of cervical measurements. The prevalence of CF ranged from 0.7-9.1%. Five studies compared composite measures of PCCR (ie, CL and CF) with short CL alone and consistently reported improved screening performance. Among 3 TVU studies, gains in sensitivity ranged from 5-27%, and increases in positive likelihood ratio ranged from 3-16. Our findings suggest that composite measures of PCCR might serve as valuable screening targets. High-quality interdisciplinary studies that integrate epidemiologic approaches are needed to test this hypothesis and to accelerate the translation of advances in cervical pathophysiology into effective preventive interventions.
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI. Electronic address: youliqing08@gmail.com.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI.
authors.forename: Mathew
authors.initials: M
authors.lastname: Reeves
authors.affiliation: Department of Obstetrics and Gynecology, University of Alabama at Birmingham, Birmingham, AL.
authors.forename: John
authors.initials: J
authors.lastname: Owen
authors.affiliation: Department of Obstetrics and Gynecology, Northwestern University, Evanston, IL.
authors.forename: Louis G
authors.initials: LG
authors.lastname: Keith
mesh_terms: D058070:Asymptomatic Diseases; D054791:Cervical Length Measurement; D020070:Cervical Ripening; D002584:Cervix Uteri / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007747:Labor Stage, First; D008403:Mass Screening; D007752:Obstetric Labor, Premature / Q000175:diagnosis* / Q000000981:diagnostic imaging; D010808:Physical Examination; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D047928:Premature Birth / Q000175:diagnosis* / Q000000981:diagnostic imaging; D018570:Risk Assessment / Q000379:methods*; D016216:Ultrasonography, Prenatal
keywords: epidemiology; precocious cervical ripening; precursor; prediction; preterm delivery; screening; translational research