Hyperstimulation contraction stress tests: an evaluation of outcome by test pattern.

Contraction stress tests (CSTs) interpreted as equivocal, with hyperstimulated contractions accompanied by late decelerations (hyperstimulation CSTs), were analyzed by test pattern and outcome and compared to a control group with negative CSTs. Outcome was evaluated for subsequent abnormal CST, low Apgar score, the presence of meconium, and cesarean section for fetal distress. Patients with hyperstimulation CSTs and solitary late decelerations, and the remainder of the test interpretable as a negative CST, had the least morbidity. In both the presence and absence of 10-minute negative windows, patients with more than one late deceleration were at significantly higher risk for cesarean section for fetal distress than controls. It would seem warranted in the presence of hyperstimulation CSTs, therefore, to repeat the CST within 24 hours regardless of the presence of a negative window.