Determination of pH or lactate in fetal scalp blood in management of intrapartum fetal distress: randomised controlled multicentre trial.
OBJECTIVE
To examine the effectiveness of pH analysis of fetal scalp blood compared with lactate analysis in identifying hypoxia in labour to prevent acidaemia at birth.


METHODS
Randomised controlled multicentre trial.


METHODS
Labour wards.


METHODS
Women with a singleton pregnancy, cephalic presentation, gestational age >or=34 weeks, and clinical indication for fetal scalp blood sampling.


METHODS
Standard pH analysis (n=1496) or lactate analysis (n=1496) with an electrochemical microvolume (5 mul) test strip device. The cut-off levels for intervention were pH <7.21 and lactate >4.8 mmol/l, respectively.


METHODS
Metabolic acidaemia (pH <7.05 and base deficit >12 mmol/l) or pH <7.00 in cord artery blood.


RESULTS
Metabolic acidaemia occurred in 3.2% in the lactate group and in 3.6% in the pH group (relative risk 0.91, 95% confidence interval 0.61 to 1.36). pH <7.00 occurred in 1.5% in the lactate group and in 1.8% in the pH group (0.84, 0.47 to 1.50). There was no significant difference in Apgar scores <7 at 5 minutes (1.15, 0.76 to 1.75) or operative deliveries for fetal distress (1.02, 0.93 to 1.11).


CONCLUSIONS
There were no significant differences in rate of acidaemia at birth after use of lactate analysis or pH analysis of fetal scalp blood samples to determine hypoxia during labour.


BACKGROUND
ISRCT No 1606064.
Wiberg-Itzel
E
E
Departments of Obstetrics and Gynaecology Söder Hospital, Stockholm, Sweden.
Lipponer
C
C
Norman
M
M
Herbst
A
A
Prebensen
D
D
Hansson
A
A
Bryngelsson
A-L
AL
Christoffersson
M
M
Sennström
M
M
Wennerholm
U-B
UB
Nordström
L
L
D000140:Acidosis, Lactic / Q000151:congenital / Q000517:prevention & control*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry*; D005316:Fetal Distress / Q000517:prevention & control*; D005311:Fetal Hypoxia / Q000175:diagnosis*; D005323:Fetal Monitoring / Q000379:methods; D005333:Fetus; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood*; D018743:Perinatal Care / Q000379:methods; D011247:Pregnancy; D012535:Scalp / Q000098:blood supply*
D019344:Lactic Acid