Assessment of Cervical Length, Shape and Consistency Between 18-24 Weeks Gestational Age by Transvaginal Ultrasound for Prediction of Preterm Labor

Abstract

Background: Preterm labor is the presence of uterine contractions of sufficient frequency and intensity to affect progressive effacement and dilation of the cervix prior to term gestation. Shortening and funneling of the cervix was first described to be associated with the diagnosis of cervical incompetence, Transvaginal sonographic measurement of cervical length could be used to predict a risk for preterm delivery for a significant proportion of preterm births. Cervical length is measured by transvaginal ultrasound from internal os to external os while the urinary bladder is empty.Objective: To determine the value of measurement of cervical parameters by transvaginal ultrasound between 18 and 24 weeks' gestation in the prediction of spontaneous preterm delivery. Patients and Methods:The study was carried out at Bab EL-Sha'aria University Hospital between 1/10/2018 and 31/12/2019 on 200 primigravida women with single pregnancy and intact membranes. Women with scarred uterus, women with chronic medical diseases or obstetric problems, women who underwent cerclage and fetal anomalies were excluded from the study. For all participants, transvaginal ultrasound was done between 18 and 24 weeks' gestation for measurement of cervical length, shape and consistency. Results:Infant means weight at delivery was 1589 g with SD 215 in preterm delivery, while Infant mean weight at delivery was 3024 g with SD 200 which was significant. 33.3% of preterm birth delivered vaginally, while 66.7% delivered by C.S. 62.6% of full term delivery delivered vaginally, while 37.4% delivered by C.S. No statistically significant difference was found regarding mode of delivery. Cervical length was significant in prediction of preterm labor with sensitivity 88.9%, specificity 91.2%, PPV 50.0% and NPV 98.8 %. Cervical consistency index was significant in prediction of preterm labor with sensitivity 88.9%, Specificity 93.4%, PPV 57.1% and NPV 98.8 %. Funneling was present in 33.3% of preterm delivery, and 4.4% of full term delivery which was significant. Measurement of cervical length, shape and consistency was a reliable method for prediction of preterm labor. Conclusion:Measurement of cervical length, shape and consistency by transvaginal ultrasound between 18 and 24 weeks' gestation was a reliable method for prediction of preterm labor.