Transvaginal nUltrasound Measurement of Lower Uterine Segment Myometrial Thickness for the Prediction of Preterm Labor in Twins Gestations. Observational Study

Abstract

Background: Transvaginal ultrasound evaluation of cervical length considered a good predictor of PTL and recently lower uterine segment myometrial thickness had been used for this purpose. Objectives: Evaluating the efficacy and validity of transvaginal ultrasound measurement of lower uterine segment myometrial thickness (LUS-MT) in prediction of preterm delivery (PTL) in twins pregnancies. Patients and Methods: This is an observational prospective cohort study where ninety sex (96) twins pregnant women were enrolled. LUS-MT and CL were measured by transvaginal ultrasound between 16-24 gestational weeks. All patients were scheduled for routine antenatal care till delivery and divided in two groups: preterm group and full-term group. Results: 58 patients delivered at full term and 38 patients had preterm delivery. Among patients who had preterm delivery, 25 patients (56.8%) had LUS-MT <4.26 and 2 patients (3.8%) only had LUS-MT ≥4. among patients who delivered at full term, 50 patients (96.2%) had LUS-MT ≥4.26 and 19 patients (43.2%) had LUS-MT <4.26. The best cutoff value for LUS was 4.26 mm with area under the ROC curve (AUC) 0.917, sensitivity 92.1 %, specificity 86.2%, PPV 81.3%, NPV 94.3% and Accuracy 92.1 %. Conclusion: Transvaginal ultrasound measurement of LUS-MT is an effective, precise, applicable and safe procedure in predicting the preterm labor in twins gestation with high validity than cervical length. Use of lower uterine wall as a substitution of CL measurement in order to predict population at risk of preterm labor needs to be investigated.