[Acid-base equilibrium in umbilical cord blood. Apgar score and acid-base equilibrium in umbilical cord blood as control parameters during labor].

Umbilical cord venous acid-base state was correlated to Apgar score at 1 and 5 minutes and to cerebral ultrasound and other clinical parameters in 295 consecutive deliveries. We present normal values for the whole sample and for normal vaginal deliveries. Most of the acidotic babies (pH less than 7,24) were clinically healthy (80% did not need intensive care in a neonatal department) and had normal Apgar scores (1 min score greater than 7 = 79% and 5 min score greater than 7 = 94%). Only a few of the babies transferred to the neonatal department were acidotic (13%) and had low Apgar scores (1 min score less than 7 = 15% and 5 min score less than 7 = 6%). The prognostic value of the three parameters for neonatal health is low using our definition of acidosis. It remains to be seen if acidosis without clinical symptoms of any significance has any influence on later development. Acid-base state showed better correlation with the optimal time of second stage of labour than Apgar score did. We found a slightly higher pH and a significantly higher base-excess with a long, as against a short second stage and pushing time. There was no difference between the second stage of delivery and the time of active pushing what concerns pH and base-excess. We do not recommend umbilical cord acid-base state as a routine for all deliveries. It should be used only in selected cases.