The nonstress test: the value of a single acceleration in evaluating the fetus at risk.

Utilization of the nonstress test in the high-risk pregnancy as the sole test for the assessment of fetal welfare is reported. A total of 1,005 tests were performed on 367 patients. A single acceleration in response to fetal movement was deemed sufficient to classify a fetus as reactive, and when present was associated with a corrected perinatal loss of zero. A nonreactive pattern predicted the four stillbirths in the series.