Changes in Cesarean section scar dimensions during pregnancy: a prospective longitudinal study

• Published in: Ultrasound in obstetrics & gynecology 2013-05, Vol.41 (5), p.556-562
• Main Authors: Naji, O., Daemen, A., Smith, A., Abdallah, Y., Saso, S., Stalder, C., Sayasneh, A., McIndoe, A., Ghaem‐Maghami, S., Timmerman, D., Bourne, T.
• Format: Article
• Language: English
• Subjects: Adult; Analysis of Variance; Cesarean Section - adverse effects; Cesarean section scar; Cicatrix - diagnostic imaging; Cicatrix - pathology; Female; Humans; Pregnancy; Pregnancy Complications - diagnostic imaging; Pregnancy Complications - pathology; Pregnancy Outcome; Pregnancy Trimesters; Prospective Studies; transvaginal ultrasonography; Ultrasonography, Prenatal; Uterine Rupture - etiology; Uterine Rupture - pathology; VBAC
• ISSN: 0960-7692; 1469-0705
• DOI: 10.1002/uog.12334

ABSTRACT Objectives To describe changes in Cesarean section (CS) scars longitudinally throughout pregnancy, and to relate initial scar measurements, demographic variables and obstetric variables to subsequent changes in scar features and to final pregnancy outcome. Methods In this prospective observational study we used transvaginal sonography (TVS) to examine the CS scar of 320 consecutive pregnant women at 11–13, 19–21 and 32–34 weeks' gestation. For scars visible on TVS, the hypoechoic part was measured in three dimensions and the residual myometrial thickness (RMT) was also measured. Analyses were carried out using one‐way repeated measures ANOVA and mixed modeling. The incidence of subsequent scar rupture was recorded. Results The CS scar was visible in 284/320 cases (89%). Concerning length and depth of the hypoechoic part of the scar and RMT, the larger the initial scar measurement, the larger the decrease observed during pregnancy. For the hypoechoic part of the scar, the width increased on average by 1.8 mm per trimester, while the depth and length decreased by 1.8 and 1.9 mm, respectively (false discovery rate P