Elimination of fetal scalp blood sampling on a large clinical service

To describe the use of fetal scalp blood sampling on a large teaching service over 7 years and to assess any association between changes in use and the rates of cesarean delivery for fetal distress and of various indirect indicators of perinatal asphyxia in term infants.

We reviewed computerized and tabular data bases for fetal scalp blood sampling, cesarean delivery for fetal distress, Apgar score, and the clinical diagnoses of asphyxia and meconium aspiration syndrome for the years 1986-1992.

Live births averaged 16,330 annually. The rate of fetal scalp blood sampling for the first 3 years of the study period was 1.76%, consistent with the rate of 1.5-2.0% noted for the preceding decade at our institution. An increase in sampling in 1987 was followed by a steady decline over the next 4 years, to a low of 0.03% in 1992. During the period of declining scalp pH usage, there was no increase in the cesarean rate for fetal distress, low Apgar score (less than 5 at 5 minutes) requiring neonatal intensive care unit admission, or the clinical diagnosis of perinatal asphyxia or meconium aspiration syndrome.

Fetal scalp blood sampling has been virtually eliminated without an increase in the cesarean rate for fetal distress or an increase in indicators of perinatal asphyxia. The role of fetal scalp blood sampling in clinical practice is questioned.