Nonstress testing and contraction stress testing

Antepartum fetal heart rate (FHR) testing, including the nonstress test and contraction stress test, has evolved in clinical usage over the past 3 decades. Although the nonstress test has become a standard of care in high- risk pregnancy, it has been modified by the use of fetal stimulation (vibroacoustic stimulation) and the addition of automated fetal movement recording (actocardiotocography). In all of its formats, antepartum FHR testing has been associated with reduction of preventable fetal loss. More recently, there have been attempts to improve test efficacy by computer- enhanced approaches.