Correlation of fetal heart rate patterns and fetal pH with neonatal outcome.

Fetal monitoring data in 200 consecutive cases was evaluated in the second hour prior to delivery to determine how neonatal outcome could be most accurately predicted. It was found that the correlation between ominous fetal heart rate-uterine contraction (FHR-UC) patterns and a depressed Apgar score at 1 minute was, at best, 37%. However, where the last fetal scalp blood pH (FSB-pH) was less than or equal to 7.2, neonatal depression occurred in 88% of cases. FSB-pH, therefore, provided a more reliable means of diagnosing fetal distress.