to assess the agreement between saline contrast sonohysterography (SCSH) and transvaginal sonography (TVS) in the evaluation of cesarean section scar defect (CSD) regarding its width, depth, and shape and also in assessing the anterior myometrium, and residual myometrium related to the scar.

a prospective study during the period between August 2017 and January 2018 was conducted in which 102 consecutive participants underwent primary cesarean section in Ain Shams University Maternity Hospital were assessed six weeks after CS to evaluate for CSD presence by using both SCSH and TVS.

CSD could be detected only in 59.8% of women by TVS and 70.5% by SCSH with good agreement strength (Cohen kappa = 0.805). TVS was 84.72% sensitive and 100.00% specific in identifying CSD diagnosed by SCSH. The PPV, NPV, and accuracy of TVS were 100.00%, 73.17%, and 89.21%, respectively.

The mean anterior myometrial thickness (AMT) did not differ when assessed by both TVS and SCSH, while the mean niche width was 2.56 ± 1.98 mm with SCSH compared to 2.17 ± 1.63 mm with TVS(r = 0.954), and its mean depth was 2.76 ± 2.02 mm for SCSH and 1.57 ± 1.51 mm in TVS(r = 0.812). The mean residual myometrium was 10.09 ± 2.74 mm in SCSH while was 11.18 ± 2.50 mm for TVS(r = 0.914)

cesarean scar defects in non-pregnant women are better evaluated at SCSH than at unenhanced TVS as more defects detected by SCSH and better evaluation of its shape, borders and size.