Ultrasound examination of the cesarean scar in the prognosis of pregnancy outcome

Objective. To study the state and time of thinning of uterine scars after cesarean section (CS) in pregnant women using ultrasound monitoring. Materials and methods. The study included 148 pregnant women at periods of 6-12, 13-20, 21-29, 30-36 and 37-40 weeks gestation; the patients were divided into groups based on the initial thickness of the residual myometrium in the scar area; pregnancy outcomes were studied. Results. Patients in group A whose residual myometrium was more than 3 mm had a late (by 37 weeks) and gradual (on average, 1 mm per trimester) thinning of the scar. The outcomes were a full-term pregnancy in 89.1% of patients, and preterm delivery at 30-36 weeks in 10.9% of cases (vaginal delivery in 17.2%, CS in 82% of cases). Patients of group B whose residual myometrium was 2-3 mm had a full-term pregnancy in 84.6% of cases, preterm delivery at 30-36 weeks in 15.4% (CS in 92.3%; CS and hysterectomy in 7.3% of cases). Pregnant women in group C had residual myometrium less than 2 mm, and its thickness was less than 1 mm in 45.7% of them at 26 weeks of gestation. Patients in this group had a high incidence of placenta previa and placenta increta (11.3%) and adverse outcomes (full-term pregnancy in 31.4%, preterm delivery at 30-36 weeks in 31.4%, preterm delivery at 22-29 weeks in 11.4% of cases). CS was performed in 57.7%, CS and metroplasty were done in 8.5%, CS and hysterectomy were performed in 5.65% of cases. Preterm delivery at 22 weeks was noted in 28.1% of cases (metroplasty - 22.5%, hysterectomy - 5.65%). Conclusion. Pregnant women whose residual myometrium is 1 mm thick or less in the period up to 26 weeks gestation are an extremely high-risk group and require special monitoring (it is recommended to perform ultrasonography at 12, 18, 22, and 26 weeks gestation).

cesarean section, uterine scar, thickness of the residual myometrium