ABSTRACT
Objective To analyze the effect of cervical canal length on maternal and neonatal outcomes in placenta previa and the predictive value of transvaginal ultrasound measurement of cervical canal length for emergency early cesarean section.Methods From January 2014 to December 2017,63 pregnant women with placenta previa in the General Hospital of Changzhi Lu'an Group were selected in this study .The length of the cervical tube was meas－ured by vaginal ultrasound in the late pregnancy .According to the length of cervical canal during delivery ,63 cases were divided into control group (cervical canal length ＞25cm,39 cases) and study group(cervical canal length ≤25cm,24 cases).The maternal and infant outcomes of the two groups were compared ,and the diagnostic efficacy of the cervical canal length to the early cesarean section of the placenta preg before 36 weeks of pregnancy was assessed by drawing the receiver operating characteristic curve to evaluate the area and the best diagnostic threshold under the curve,and calculated the sensitivity and specificity .Results The gestational weeks of delivery in the study group was significantly shorter than that in the control group (t＝5.95,P＜0.01).The incidence rate of premature delivery , prepartum hemorrhage and premature cesarean section before 36 weeks of pregnancy in the study group were significantly higher than those in the control group (χ2＝10.32,10.37,22.97,all P＜0.05).There were no statistically significant differences in the rate of blood transfusion and the gender of the newborns between the two groups ( χ2＝0.001, 0.010,all P＞0.05).The birth weight and the 5 min Apgar score in the study group were significantly lower than those in the control group(t＝5.48,4.65,all P＜0.05).The incidence rate of neonatal asphyxia in the study group was significantly higher than that in the control group (χ2＝5.19,P＜0.05).The area of the cervical canal length was 0.87,with the sensitivity of 84.62%,the specificity was 78.38%,and the best diagnostic threshold was 26.5 mm for the pregnant women who was predicted the placenta previa before 36 weeks of pregnancy.Conclusion The incidence rates of adverse outcomes ,such as premature birth,prenatal bleeding and neonatal asphyxia ,are higher in pregnant women with shorter cervical tube length .The measurement of cervical canal length by vaginal ultrasound for pregnant women with placenta previa can be used as an important evaluation method to predict the early cesarean section of pregnant women,and help to strengthen the clinical intervention ,take management to prevent serious perinatal compli－cations.