[The diagnostic value of ultrasonotomography with reference to previous cesarean section scars during full term pregnancy (author's transl)].

It is very important to diagnose the condition of previous cesarean section scars when deciding the delivery mode. We have investigated the use of ultrasonotomography and obtained the following results. 1. As it is impossible to measure exact thickness of cesarean section scars, we have measured the interval of bladder wall to fetal surface (B-F interval) before delivery. 2. As a control group, 24 pregnant women with no history of cesarean section were examined. In twenty one cases (87.5%) we found a minimum B-F interval of 4 to 7mm, and no cases measured under 4mm. 3. Twenty one pregnant women were examined by ultrasonotomography, and of these 15 cases with previous cesarean section scars were revealed upon operation. Three cases had incomplete dehiscence, where B-F interval was 0mm. Another four cases had mild thin cesarean scars, where the minimum B-F interval was 3mm in two instances, 4mm in one and 5mm in the other. In another eight cases, no thin cesarean section scars were observed and the minimum B-F interval were 4 to 7mm in six cases but in two cases, the minimum B-F interval could not be detected by our machines. These results suggest that ultrasonotomography is useful to detect incomplete dehiscence, but difficult to do mild thin cesarean section scars.