Medline ® Abstract for Reference 18

The Departments of Obstetrics and Gynaecology of the Hvidovre University of Copenhagen and the Free University of Amsterdam collaborated in a study on the relationship of maternal and fetal acid-base state in the intrapartum period. Transcutaneous PCO2 levels of mother (tcPCO2m) and fetus (tcPCO2f) were continuously recorded in 52 patients during labour. TcPCO2f and tcPCO2m correlated significantly (r = 0.42, P<0.002). During the first stage of labour, a rather stable level was found for tcPCO2f (7.7 +/- 1.6 kPa) and tcPCO2m (4.4 +/- 0.8 kPa). TcPCO2m decreased significantly to 3.8 +/- 0.7 kPa (P<0.01) in the hour before full cervical dilatation, probably due to maternal hyperventilation as a reaction to painful uterine contractions. TcPCO2f likewise showed a tendency to a decrease to a mean value of 7.4 +/- 1.5 kPa. In eight cases epidural analgesia was applied because of painful uterine contractions. Prior to the epidural analgesia, tcPCO2m (3.8 +/- 0.8 kPa) and tcPCO2f (6.7 +/- 1.7 KPa) were significantly lower in this subgroup compared to the total population. After pain relief by application of epidural analgesia, tcPCO2m and tcPCO2f returned to the population mean.