Role of 2D Doppler in the Prediction of Preterm Labor in High-risk Patients in Banha University Hospital; A Prospective Cohort Study

Background/Objective: Preterm labor is a major obstetric problem. Several ultrasound parameters are used to predict Preterm labor. This study aimed to assess the role of Doppler ultrasound in predicting preterm labor in high-risk patients. Patients and methods: This observational cohort study was conducted between January and August 2024 at Banha University Hospital on 80 high-risk pregnant women for Preterm labor. We performed a Doppler examination of uterine arteries (S/D ratio, pulsatility index, and the presence or absence of notch unilaterally or bilaterally). UTA evaluation was conducted during three pregnancy periods: the first examination was 18-22 weeks +6 days; the second visit was 28-31 weeks; and the third visit was 32- 35+6. The primary outcome was the occurrence of spontaneous PTB before 37 weeks of gestation. Various statistical tests were used, including ANOVA for comparing means, Tukey’s test for multiple comparisons, and Chi-square test or Fisher’s exact test for qualitative data. Sensitivity, specificity, and predictive values were calculated with 95% confidence intervals. A significance level of p<0.05 was used. Results: Sixty-eight women were included in the final analysis. Preterm delivery occurred in 50 patients (15 between 28-34 weeks, and 35 delivered 34 w +1 d- 36w+6). There was no significant difference in the S/D ratio for the likelihood of preterm delivery between 18.0-22+6 weeks and 28-32 weeks. A significant correlation was observed at 32+1-36+6 weeks, suggesting that it could predict preterm birth at this stage. No significant correlation was found between the UtA-PI and the likelihood of preterm birth at 18-22 weeks and 28-32 weeks. However, at 32+1-36+6 weeks, a significant correlation was identified between the S/D ratio and the likelihood of preterm birth, indicating its potential as an indicator at this stage. Conclusion: The S/D ratio and UtA-PI showed potential as indicators for preterm birth likelihood at specific stages of pregnancy.