Examination of previous caesarean section scars by ultrasound.

We examined 84 lower segment caesarean section scars by ultrasonography near term. Seventy scars showed good healing with a thickness of the lower uterine segment of more than 3 mm; 14 scars showed poor healing with a thickness of less than 2 mm and loss of continuity. Among 70 patients with good healing, 24 patients delivered vaginally but the remaining 46 patients have had repeat caesarean sections for other obstetric indications. Intraoperative findings in these 46 patients were as follows: Grade I (no thinning of the lower uterine segment), 42; Grade II (thinning and loss of continuity of the lower uterine segment but fetal hair not visible), 4; Grade III (thinning of the lower uterine segment and fetal hair visible), 0. Fourteen patients with poor healing had repeat caesarean sections. Intraoperative findings in these 14 patients were as follows: Grade I, 0; Grade II, 9; Grade III, 5. These results indicate that ultrasound examination detect thinning of the lower uterine segment and may help to determine management.