Contraction Stress Testing

The Challenge

Fetal health may be assessed using the contraction stress test (also called “oxytocin challenge test”). This test is somewhat analogous to an exercise stress test for the evaluation of adult cardiac function as problems or weaknesses that are normally compensated for at rest may become apparent with stress. In the contraction stress test the fetal–placental–maternal unit is stressed through uterine contractions. The resulting periodic deprivation of uterine blood flow can be used to evaluate the robustness of the fetal–placental condition.

• Scope of the Problem: Of pregnancies, 3%–12% are at risk because of gestations that extend beyond term. More pregnancies may be compromised by maternal disease states that affect fetal health or placental function (eg, hypertension, diabetes), resulting in abnormalities of fetal growth and amniotic fluid volume and other problems.

• Objectives of the Test: To assess fetal health and reserve.