Ultrasound evaluation of uterine scar after Cesarean section and next birth

Cesarean section (Sectio Caesarea) is a surgical method for the completion of delivery. After various historical modifications of operative techniques, modern approach consists in the transverse dissection of the anterior wall of the uterus. The rate of vaginal birth after cesarean section was significantly reduced from year to year, and the rate of repeated cesarean section is increased during the past 10 years. Evaluation of scar thickness is done by ultrasound, but it is still debatable size of thick scar that would be guiding "cut-off value" for the completion of the delivery method.

The aim was to examine the most accurate ultrasonic method for assessing thickness scar on the uterus after previous cesarean delivery and determine the threshold thickness of scar that would allow the completion of birth vaginally.

Conducted is prospective study of 108 pregnant women aged 20-42 years, who had previously had a Caesarean section. Diagnostic accuracy in assessing the success of scar scale by evaluation of delivery (spontaneous or caesarean section). Measurements were carried out by 2D and 3D ultrasound machines in the 20, 38-40 week of gestation and 48 hours after birth.

Tests have shown that there is a statistically significant difference in the rates of specificity (0.04), sensitivity (0.05), PPV (0.01) and NPV (0.01) between 2D and 3D ultrasound. Ultrasound images of uterine muscle scar after prior cesarean section are better by 3D methods. The marginal value, "cut-off value" thick scar, which provides the possibility of vaginal birth after previous incision was 3.5 mm.

The study showed that ultrasound measurement of 3D ultrasound thick scar on the uterus after previous cesarean section has practical application in determining the mode of delivery among pregnant women who have previously given birth by Caesarean section.