Clinical significance of early (< 20 weeks) vs. late (20-24 weeks) detection of sonographic short cervix in asymptomatic women in the mid-trimester.

TLDR: The aim of this study was to determine whether the risk of early spontaneous preterm delivery in asymptomatic women with a sonographic cervical length of ≤ 15 mm in the mid‐trimester changes as a function of gestational age at diagnosis.

Abstract: Objective—The aim of this study was to determine whether the risk of early spontaneous preterm delivery (sPTD) in asymptomatic women with a sonographic cervical length ≤15 mm in the mid-trimester changes as a function of gestational age at diagnos Methods—This cohort study included 109 asymptomatic patients with a sonographic sonographic cervical length ≤15 mm diagnosed at 14–24 weeks of gestation. Women with a multifetal gestation, cerclage, and those with a cervical dilatation >2 cm were excluded. The study population was stratified by gestational age at diagnosis (<20 weeks vs. 20–24 weeks) and by cervical length (≤10 mm vs. 11–15 mm). The primary outcome variables were PTD <28 and <32 weeks’ gestation and the diagnosis-to-delivery interval. Results—1) The median gestational age at diagnosis of a short cervix before 20 weeks and at 20–24 weeks was 18.9 and 22.7 weeks, respectively; 2) women diagnosed before 20 weeks had a higher rate of sPTD at <28 weeks (76.9% vs. 30.9%; p<0.001) and at <32 weeks (80.8% vs. 48.1%; p=0.004), and a shorter median diagnosis-to-delivery interval (21 vs. 61.5 days, p=0.003) than those diagnosed at 20–24 weeks; 3) The rate of amniotic fluid “sludge” was higher among patients diagnosed at <20 weeks of gestation than those diagnosed between 20 and 24 weeks (92.3% vs. 48.2%;p<0.001). Conclusions—Asymptomatic women with a sonographic cervical length ≤15 mm diagnosed before 20 weeks have a dramatic and significantly higher risk of early preterm delivery than women diagnosed at 20–24 weeks. These findings can be helpful to physicians in counseling these patients, and may suggest different mechanisms of disease leading to a sonographic short cervix before or after 20 weeks of gestation.