[Lowering the cesarean section rate by exclusion of cardiotocographically suspected acidosis using fetal blood gas analysis].

In 871 deliveries out of a total of 3980 effected during 1980-1982 at the Winterthur Gynaecological Hospital, we found it necessary to perform one or several microanalyses of blood (blood gas analyses) sub partu. Among these, we found retrospectively that in 22 cases the microanalysis of the blood gas had prevented us from performing caesarean section which would have seemed necessary if we had relied on the cardiotocographical findings alone. Micro-analysis of blood gas made it possible to exclude the presence of pre-acidosis or acidosis which would have made Caesarean section imperative; in all these cases, normal delivery via the vagina was achieved, and in no case did this result in severe acidosis. All newborn had a 5-minute Apgar score of 7 and higher. We can conclude from these results, therefore, that the indication for an immediate termination of delivery via Caesarean section should not depend solely on a pathological cardiotocogram; the final decision should be arrived at only after micro-analyses of blood gas have confirmed the presence of foetal pre-acidosis or acidosis.