ABSTRACT
Blood should be obtained for acid–base status from an isolated segment of umbilical cord following delivery of any potentially acidotic fetus, including: Intrapartum CTG, cases where fetal scalp blood has been sampled, instrumental vaginal delivery, preterm delivery, breech vaginal delivery, IUGR, placental abruption, cord prolapse, baby born with a low apgar score, and fetal abnormality. A quality control check must be made on the analyser as directed by the manufacturer. A 10 cm segment of cord is clamped immediately after delivery of the baby. Samples of cord artery and vein are obtained with pre-heparinized syringes. The arterial sample is more difficult to obtain, but this is the sample that is representative of the baby’s acid–base balance. Unless both arterial and venous samples are obtained, it cannot be established that the umbilical artery has been sampled. The segment of cord may be left at room temperature for up to 30 minutes (or in ice for up to 1 hour) before analysis.
