Payesh (Jul 2006)
Relationship between preterm labor and the length of the cervical canal
Abstract
Objective (s): To determine the relationship between cervical length at 16 and 24 weeks of gestation and the occurrence of preterm labor. Methods: A prospective cohort study was performed on 153 pregnant women in two groups (75 and 78 person) after measuring cervical length with vaginal sonography. We calculated the incidence preterm labor m both groups, plus the sensitivity, specificity, positive and negative predictive values for cervical length. Results: The incidence of preterm labor was 17.3% ( 13/75) in the group with cervix length of less than 35 mm and 6/4% (5/78) in the group with cervical length ;::JS mm. The relative Risk was 2.7 (95% CI=l.3-4.5). Sensitivity, specificity, positive and negative predictive value of cervical length on preterm delivery with a cut-off point of 35 mm were 72%, 54%, 17% and 93% respectively. In the multivariate analysis of job, education, parity, gravidity and cervical length only cervical length was significantly related to preterm delivery (P<0.01). The cervical length also had a significant correlation with preterm delivery (P<0.001, r =0.61). Conclusion: Cervical length between 16 and 24 weeks of gestation is a strong-predictor of preterm labor.
