Print: Chapter 15. Antepartum Assessment

In this chapter, the evolution of techniques employed to forecast fetal well-being is considered. The focus is on testing procedures that depend on fetal physical activities, including movement, breathing, amnionic fluid production, and heart rate. According to the American College of Obstetricians and Gynecologists (1999), the goal of antepartum fetal surveillance is to prevent fetal death. In most cases, a normal test result is highly reassuring, because fetal deaths within 1 week of a normal test are rare. Indeed, negative-predictive values—a true negative test—for most of the tests described are 99.8 percent or higher. In contrast, estimates of the positive-predictive values—a true positive test—for abnormal test results are quite low and range between 10 and 40 percent. Importantly, the widespread use of antepartum fetal surveillance is primarily based on circumstantial evidence because there have been no definitive randomized clinical trials.