To evaluate the rate of discrepancy between pH and lactate values in fetal blood sampling (FBS). To evaluate differences in obstetric management in response to combined tests (pH and lactate) and single tests (pH or lactate).
Descriptive study.
Uppsala University Hospital, Sweden.
Labors monitored by FBS during one year (n=241).
Discrepancy in the combined tests was defined as a test having one abnormal and one normal value. Abnormal pH was defined as 7.24 or lower and abnormal lactate as 4.2 or higher. The results were categorized according to whether the test was normal or abnormal and according to whether it was a combined or single analysis.
Discrepancy between pH and lactate values in combined tests. Frequency of operative delivery for fetal distress (ODFD). Time interval from the last FBS to ODFD.
In the combined tests with abnormality, a discrepancy between pH and lactate values occurred in 55%. The mean time interval from the last FBS to ODFD was longer in combined tests with one abnormal compared with two abnormal test results, 75 vs. 37 minutes (p