Uterocervical angle versus cervical length in the prediction of spontaneous preterm birth in women with history of spontaneous preterm birth: a prospective observational study.

BACKGROUND: Preterm delivery is a leading cause of neonatal mortality and morbidity. History of spontaneous preterm birth is the greatest risk factor for another preterm delivery. So, every effort should be made to prevent the recurrence of preterm delivery in this vulnerable group. This study aimed to evaluate the predictive ability of the anterior uterocervical angle and cervical length in preterm birth. PATIENTS AND METHODS: This was a prospective cohort study that included 70 patients with a history of spontaneous preterm birth. Ultrasound measurements of cervical length and anterior uterocervical angle were set to be measured for each patient at three visits; first between 16 0/7 and 24 0/7 weeks, second between 24 1/7 and 32 0/7 weeks, and the third was between 32 1/7 and 36 6/7 weeks. The correlation between both measures and the prediction of preterm birth among study participants was the primary outcome of the study. Neonatal outcome among the study patients was a secondary measure of outcome. RESULTS: The incidence of preterm birth among study participants was 31.41%. Cervical length and uterocervical angle showed progressive decrease and increase respectively throughout pregnancy. At the 2nd visit, the two measures were significantly different between those who delivered at term and those with preterm delivery with the cervical length being significantly shorter in the preterm arm (3.0 ± 0.49 versus 3.38 ± 0.36, p < 0.001) and uterocervical angle being significantly bigger among the same arm (110.1 ± 18.48 versus 84.42 ± 12.24, p < 0.001). A uterocervical angle > 89.8° at the second visit predicted preterm birth with 81.8% sensitivity and 70.8% specificity while cervical length ≤ 3.22 cm at the second visit predicted preterm birth with 68.1% sensitivity and 62.5% specificity. Multivariant logistic regression analysis showed that uterocervical angle > 89.8° at the second visit increased the odds ratio for preterm birth by 9. CONCLUSION: Uterocervical angle can be a useful ultrasound marker for the prediction of preterm birth among high risk patients. A cutoff value of 89.8° can be used as a threshold above which prophylactic measures such as cervical cerclage or progesterone therapy can be provided. TRIAL REGISTRATION: NCT05632003 (First posted date: 30/11/2022).

Diagnostic Accuracy of Placental Thickness in Lower Uterine Segment Measured by Ultrasound in Prediction of Placenta Accreta Spectrum in Patients with Placenta Previa. A Diagnostic Test Accuracy Study.

Objective: The aim of the study was to evaluate the association between placental thickness and placenta accreta spectrum (PAS) in patients with placenta previa. Materials and Methods: In this prospective study, 40 patients diagnosed with placenta previa were included. The maximum placental thickness in the lower uterine segment was obtained using a transabdominal scan. For the image to be deemed suitable, a midline sagittal section of the lower uterine segment (with the implanted placenta) and the cervical canal, with the intervening urinary bladder had been required. Intraoperative attendance was ensured for the detection of cases with spontaneous separation and cases with morbid adherence. All specimens removed were sent for histopathology to confirm PAS. The primary outcome of the study was to detect a threshold of placental thickness which can be used as a cut-off value in such screening test. The number of units of packed RBCs transfused during the operation and bladder injury were secondary measures of outcome. Results: Forty patients were included in the study; 20 patients were ultimately diagnosed with PAS while 20 patients did not have PAS. Mean placental thickness was significantly higher in the PAS patients compared with those with no invasive placentation (61.00 mm Vs 43.00 mm, P value 0.000). Using receiver operating characteristic (ROC) curve, a threshold placental thickness of 58mm was associated with 55% sensitivity, 90% specificity, 84.6% positive predictive value, and 66.7% negative predictive value. Multivariate logistic regression showed that placental thickness more than 58mm and having past history of more than three cesarean sections were independent risk factors for PAS among patients with placenta previa. Conclusion: Placental thickness in the lower uterine segment is increased in patients with placenta previa with PAS compared to those with no PAS. Such finding can be implemented into clinical practice by using placental thickness as a screening test for PAS in patients with placenta previa. ClinicalTrialsgov ID: NCT05500404.