If the exchange of oxygen and carbon dioxide between the maternal and fetal circulations is interrupted during labour, fetal acidosis may occur. The purpose of this study was to assess the relation between SmcO2 determined by near infrared spectroscopy (NIRS) within the last 30 minutes of labour and umbilical cord blood acid-base status measured immediately at birth. A specially designed optical probe was inserted through the dilated cervix and placed against the fetal head (n=41). Changes in cerebral oxyhaemoglobin and deoxyhaemoglobin concentrations were measured continuously in each fetus to within 20 minutes of delivery (mean 11 minutes). In 33 fetuses it was possible to calculate a mean value for SmcO2 over a 10 minute period of 46% (range 21-71%). There was a statistically significant positive correlation between SmcO2 and both the umbilical artery pH (range 7.09-7. 43) (r=0.82, p<0.001) and base excess (range -11.0 to 0.7 mmol.L-1) (r=0.73, p<0.001). We conclude that SmcO2 measured within 30 minutes of delivery is related to fetal acid-base balance at birth.
About this article
Cite this article
Aldrich, C., D'Antona, D., Wyatt, J. et al. 6 HUMAN FETAL CEREBRAL OXYGEN SATURATION (SmcO2) MEASURED DURING LABOUR CAN PREDICT ACID-BASE STATE AT DELIVERY. Pediatr Res 36, 1 (1994). https://doi.org/10.1203/00006450-199407000-00006