Sonographic assessment of post-cesarean section uterine scar in pregnant women.

PURPOSE

To detect location of uterine cesarean scar in relation to cervix in pregnancies with previous cesarean section (CS) and to compare location between elective and emergent previous CS.

STUDY DESIGN

Prospective study, 91 pregnant women with previous low transverse CS. Two groups: previous elective [36 (39.6%)] and emergent CS [55 (60.4%)]. Transvaginal ultrasound was performed between 14 and 16 weeks. Cervical length (CL) and distance between external oss to hypoechogenic line (EO-HL distance), which describes location of cesarean scar, were measured. Surgical incision was considered cervical when EO-HL distance was smaller than CL.

RESULTS

Mean CL and EO-HL distance: 45.4 + 7. 0 and 39.0 + 9.4 mm, respectively for all patients. No significant differences were observed in CL (45.9 + 6.2 vs. 45.1 + 8.5 mm; p = not significant [NS]) and EO-HL distance (40.7 + 9.7 vs. 37.9 + 9.1 mm; p = NS) between both groups. Sixty-four cases (70.3%) had cervical scar, eight (8.8%) at the level of the internal oss and 19 (20.9) in the lower uterine segment. No significant difference was observed between both groups regarding location of scar (cervix -72 vs. 67% emergent vs. elective, respectively; p = NS).

CONCLUSION

CS incisions are mostly performed in cervix, in elective as well as in emergent operations.