Prediction of the Risks of Premature Labor by Cervical Length through Perineum Ultrasonic Measurement

Objective To explore the prediction value for premature birth by cervical length( CL)through perineum ultrasonic measurement. Methods The pregnancy outcomes of 28+-36+weeks natural labor pregnant women in 60 cases and premature pregnant women in 45 cases,who visited People's Hospital of Beihai City,from Jan. to Dec. in 2012 were tracked by CL through perineum ultrasonic measurement.Results ①Among the 60 cases with normal labor check pregnant woman normal delivery( called normal natural labor group),13 cases premature labor( called premature labor group) and 32 cases with mature delivery( called omen preterm group) in 45 cases with preterm labor sign in pregnant women,the differences of the average cervical length of normal natural labor group and the premature labor group compared with omen preterm group were statistically significant( P 0. 01). ②As for the sensitivity,specificity,positive predictive value and negative predictive value of the cervical length≤20 mm,≤25 mm,≤30 mm,≤35 mm to predict premature labor,it showed that the shorter the cervix,the higher the predictive specificity and the lower the sensitivity. It reached to the maximum value of the sensitivity and specificity of preterm birth at the cervical length≤30 mm. At this point,the positive predictive value was 52%,while the negative predictive value was 95%. ③The preterm delivery rates were 52. 2% and 4. 5% of the pregnant women with preterm labor cervical length ≤ 30 mm and 30 mm,the difference was of statistical significance( P 0. 01).Conclusion Measuring CL through perineum ultrasonic measurement has a certain clinical value to predict premature labor. When the CL is ≤30 mm in the pregnant women with threatened preterm delivery,the preterm birth rate is high,which can be used as the warning line of prevention.