Transvaginal cervical length and tobacco use in Appalachian women: association with increased risk for spontaneous preterm birth
Currently ACOG recommends that a mid-term screening strategy may be considered to identify short cervix in low risk populations in an effort to prevent preterm birth. Vaginal progesterone is recommended for women with a cervical length ≤20 mm. Cerclage is recommended for women with prior spontaneous preterm birth who are already receiving progesterone supplementation and CL is <25 mm. This study examined risk factors for spontaneous preterm birth (SPB) <35 weeks among a general obstetrical population prior to these ACOG recommendations. However, cervical cerclage was a possible intervention. Study population included 1,074 patients from 1 Jan 2007-30 Jun 2008 receiving mid-trimester transvaginal ultrasounds during prenatal care at a tertiary medical center clinic. Receiver operator characteristic (ROC) curve cutoff optimal value was ≤34 mm, (n=224), corresponding to 8.9% SPB with shortened cervices compared to 1.4% in patients with normal cervices (>34 mm; n=850; p<0.001 (Area Under the Curve (AUC) 76.6, p<0.001). Cervical lengths <30 mm had 12 times the risk of SPB (p<0.001) while 30-34 mm had 5 times (p=0.005). Tobacco use (≥10 cigarettes per day), p=0.030, and low BMI, p=0.034, had additive effect. Shortened cervical length during routine screening independently predicted SPB while heavy smoking with shortened cervix during pregnancy doubled risk compared to shortened cervix alone.
Digital Commons Citation
Findley, J; Seybold, D J.; Broce, M; and Yadav, D, "Transvaginal cervical length and tobacco use in Appalachian women: association with increased risk for spontaneous preterm birth" (2015). Clinical and Translational Science Institute. 238.