Cesarean section during labor: ultrasound assessment of postoperative scar healing

The number of cesarean sections performed worldwide continues to rise each year. In Europe, cesarean deliveries account for approximately 25% of all births. Global concern about the increase in the number of operations is justified and is associated with an increase in the number of complications. An incompetent uterine scar poses significant risks for both maternal and fetal health in subsequent pregnancies. Currently, there is no “gold standard” for assessing the postoperative suture and subsequently the uterine scar, and the factors influencing its healing remain unclear. Additionally, the impact of emergency versus elective cesarean sections on scar integrity and clinical outcomes has not been completely determined.

The aim of the study was to evaluate the factors affecting postoperative suture healing following cesarean delivery during labor.

Materials and Methods: The study included 100 women with singleton pregnancies, categorized into four groups based on the degree of external cervical os dilation: 0–1 cm dilation (n = 43), 2–4 cm dilation (n = 20), >4 cm dilation (n = 24), control group – elective cesarean section (n = 13). All women underwent cesarean delivery in cephalic presentation at term, with no prior uterine scar. On the third postpartum day, all patients underwent transvaginal ultrasound to assess the postoperative suture. The evaluation included measurements of the distance between the suture and the internal and external cervical os, uterine position, suture length, width, and thickness, as well as the thickness of the adjacent myometrium above and below the suture. Additional parameters included cervical length, uterine length, width, anteroposterior uterine diameter, anteroposterior uterine cavity diameter, anterior uterine wall thickness, and posterior uterine wall thickness. 

Our study found that uterine suture thickness correlated with its distance from the internal and external cervical os: the greater the distance, the thinner the suture. Ultrasound features of the uterine suture were also influenced by uterine position, with significantly greater suture length and thickness observed in cases of uterine anteversion. Additionally, the presence of chronic diseases impacted suture healing; the thickness of the adjacent myometrium below the suture was significantly reduced in patients with arterial hypertension.

Thus, a comprehensive assessment of postoperative suture  parameters, anatomical features, and comorbid conditions may provide a more complete understanding of uterine suture healing and the likelihood of forming a competent scar.

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