Continuous labor surveillance by fetal heart rate monitoring (FHR) is highly sensible but has a poor sensitivity. Fetal scalp pH testing has, therefore, been added to overcome this lack of sensitivity (cf. Bruno Carbonne). Later, other methods were introduced. After being initially promising, fetal oxymetry, developed by Nellcor, was evaluated by five randomized studies "of varying quality". These studies showed no decrease in caesarean section and operative extraction rate or metabolic acidosis. Fetal electrocardiogram (STAN) was studied in four randomized trials. Added to continuous FHR monitoring, STAN does not reduce caesarean section or operative extraction rates compared to FHR monitoring added to fetal scalp pH testing. However, it decreases the frequency of fetal scalp pH testing. There is no comparative trial on the computerized FHR monitoring using the Oxford System.