<Tr> <Td_colspan="2"> (edit on Wikidata) </Td> </Tr> <P> A nonstress test (NST) is a screening test used in pregnancy . A cardiotocograph is used to monitor the fetal heart rate . </P> <P> The premise of the NST is that a well - oxygenated, non-acidemic fetus will spontaneously have temporary increases in the fetal heart rate (FHR). </P> <P> Vibroacoustic stimulation can wake the fetus, and is sometimes used to speed up the test or to facilitate further evaluation of a nonreactive nonstress test . </P>

Accelerations lasting less than 15 seconds throughout fetal movement