[Cerebral Doppler technic during labor using signal monitoring at the level of the fetal scalp].

The purpose of modern obstetrics is to obtain tracers of the fetal cerebral risk during labor, enabling to deliver the child before cerebral ischemia occurs. Recording of the fetal heart and measurement of acid-base balance are remarkable tracers; however, a much better precision is desired to avoid unnecessary or too late caesarean sections. Blood velocity measurement by Döppler at the level of the vessels at the base of the fetal skull is technically possible during labor; this has been demonstrated in 8 fetuses. The major cerebral index D/S during labor is 0.40 +/- 0.04, i.e. slightly lower than the mean index measured at the cord (0.50 +/- 0.07). In case of decelerations, it decreases to a mean value of 0.22 +/- 0.02. These preliminary results permit to hope that long-term measurements with continuous Döppler, of the arterial fetal cerebral flow, provide a direct and accurate tracer of the risk of cerebral ischemia during labor.