Fetal acid-base balance can be assessed in a number of ways:
●Umbilical cord blood sampling immediately after delivery
●Antepartum umbilical cord blood sampling (see "Fetal blood sampling")
●Fetal scalp blood assessment (see "Intrapartum fetal heart rate assessment", section on 'Fetal scalp blood sampling').
Umbilical cord blood analysis for evaluation of the newborn's acid-base status immediately after delivery is the most objective way of assessing the fetal metabolic condition at birth [1-3]. This information can also be useful from medical and medicolegal perspectives since it provides insight into intrapartum fetal physiology and, if normal, excludes perinatal asphyxia or hypoxia secondary to the birth process . As an example, only a minority of newborns who have low Apgar scores are acidotic at delivery [4-6], which suggests that the depression is related to factors other than prolonged hypoxia .