Intrapartum fetal surveillance: the role of fetal scalp blood sampling.

Continuous electronic fetal heart rate monitoring and fetal scalp blood sampling have traditionally played a complementary role in intrapartum fetal surveillance. Nevertheless, biochemical assessment of fetal blood pH, with the use of scalp or umbilical cord blood, is often viewed as the "gold standard" against which biophysical indicators of fetal distress must be judged. In actual clinical practice, however, fetal scalp blood sampling is only rarely used. In addition, there is a growing body of evidence to suggest that, when properly interpreted, fetal heart rate assessment may be equal or superior to measurement of fetal blood pH in the prediction of both good and bad fetal outcomes. Under certain circumstances, fetal scalp blood sampling remains a valuable clinical tool; however, we recommend a deemphasis of fetal scalp blood sampling in general clinical practice. Both theoretical and practical considerations suggest that the properly trained clinician may pursue an approach for the detection of fetal distress that does not include scalp blood sampling without either compromising his ability to detect fetal distress or significantly increasing the cesarean section rate.