The Assessment of Cervical Length and Thickness of Cesarean Section Scar as Predictors for Preterm Labor in Patients with Previous Cesarean Section: A Prospective Cohort Study

Abstract

Background: Cesarean sections (CS) have been increased all over the world. There is no doubt that CS scar from previous deliveries has an adverse effect on the function of the lower uterine segment (LUS) and the cervical canal length (CL). Objective: We examined the CL and thickness of lower uterine segment (LUS) by the antenatal ultrasound assessment to predict the occurrence of preterm birth (PTB). Materials and Methods: This is a prospective cohort study (including women with previous CS and non-scarred uterus) by ultrasonography assessment of the LUS and CL was performed to all women at the time of recruitment (18-25 weeks) and was repeated in scheduled follow-up visits tell reach term pregnancy. The study conducted between February 2021 and August 2022.The number of cases with PTB was our primary outcome. Results: Between the study (scarred uterus) n=140 and the control groups (non-scarred uterus) n=120 as regards age and body mass index (BMI) There were no significant differences. The study group showed a significant increase in PTB rate 26.1% (29/111) when compared to control group 11.8% (12/102) (p=0.008). The LUS in both groups had a significant thinning. However, the study group had more progressive thinning than the control group (5.25 ± 0.77 vs. 5.59 ± 0.80 mm, p= 0.001). According to CL, there was a progressive shortening of cervices in both groups. Conclusion:The assessment of CL and LUS thickness during antenatal care visits may improve neonatal outcomes due to its safety and feasibility.