Allie Sakowicz

Association between second-trimester cervical length and primary cesarean delivery

OBJECTIVE: To evaluate whether an increased ultrasonographic cervical length in the second trimester is associated with an increased frequency of cesarean delivery. METHODS: This is a retrospective cohort study of nulliparous women with a singleton pregnancy who underwent routine cervical length screening between 16 and 24 weeks of gestation and labored after 34 weeks of gestation at a single tertiary care hospital. Women were grouped by cervical length quartile, and the association between cervical length quartile and cesarean delivery was determined in both univariable and multivariable analyses. RESULTS: For every additional centimeter of cervical length, the odds of cesarean delivery increased by 20.3%. Similarly, the frequency of cesarean delivery increased with increasing second-trimester cervical length quartiles (17.4%, 22.3%, 21.8%, 27.7%; P<.001). This association persisted in multivariable analyses that included gestational age at delivery and induction of labor. This increased risk of cesarean delivery was primarily the result of women with arrest disorders in the first stage of labor (P<.001). CONCLUSION: Increased second-trimester cervical length quartile is associated with an increased frequency of primary cesarean delivery in nulliparous women. LEVEL OF EVIDENCE: II

The association between cervical dysplasia, a short cervix, and preterm birth

OBJECTIVE We sought to determine whether cervical dysplasia in the absence of an excisional procedure is associated with an increased risk of preterm birth (PTB) and whether that risk is independent of the presence of a short cervix. STUDY DESIGN This is a cohort study including women with a singleton pregnancy who underwent routine cervical length assessment between 18-23 6/7 weeks of gestation, stratified by cervical dysplasia (ie, no prior dysplasia, prior dysplasia but no excisional procedure, or prior excisional procedure). The frequency of a short cervix (≤2.5 cm) and PTB were compared between groups and multivariable analyses were performed to identify whether: (1) dysplasia alone or a prior excisional procedure was associated with PTB; and (2) whether these factors remained independently associated with PTB after adjusting for the presence of a short cervix. RESULTS Of the 18,528 women who met inclusion criteria, 3023 (16.3%) had prior dysplasia alone and 1356 (7.3%) had a prior excisional procedure. The frequency of a short cervix for women without dysplasia, with prior dysplasia alone, or with a prior excisional procedure was 0.8%, 1.0%, and 2.2%, respectively (P < .001). The frequency of PTB, respectively, was 6.4%, 6.5%, and 8.4% (P < .001). After adjusting for potential confounding factors, prior excisional procedure but not prior dysplasia alone was associated with PTB. CONCLUSION Having a prior cervical excisional procedure but not dysplasia alone is associated with an increased risk of PTB. This association is independent of the presence of a short cervix.

Is Midtrimester Cervical Length Associated with Preterm Birth in Women Evaluated for Preterm Labor

Abstract Objective This article aims to evaluate whether midtrimester cervical length (CL) is associated with improved prediction of preterm delivery in women presenting with preterm labor. Study Design This is a retrospective cohort study of women with a singleton gestation who underwent routine CL screening between 18 and 24 weeks of gestation between 2010 and 2014 who were later evaluated for preterm labor. Women were stratified by midtrimester CL quartile. Bivariable and multivariable analyses were performed to identify factors independently associated with preterm birth <37 weeks, <34 weeks, and delivery within 7 days of evaluation. Receiver operating characteristic (ROC) curves were created for multivariable equations with and without CL quartile to determine whether addition of CL improved the predictive capacity of the model for predicting preterm birth. Results A total of 460 women were evaluated for preterm labor and had midtrimester CL measurements available. When CL quartile was incorporated into a regression model including demographic and clinical characteristics associated with preterm birth, the area under the ROC curve was not improved (0.775 vs. 0.786, p = 0.20). Conclusion While a shorter midtrimester CL quartile is associated with an increased incidence of preterm delivery in women evaluated for preterm labor, the addition of this variable to an existing model does not improve prediction of preterm birth.