The predictive value of fetal heart rate monitoring: a retrospective analysis of 2165 high-risk pregnancies

Abstract

The predictive value of fetal heart-rate monitoring on fetal well-being was studied in 2165 high-risk pregnancies. 1883 reactive nonstress test (NST) patterns and 278 nonreactive NST patterns and 4 cases of sinusoidal pattern were obtained. Oxytocin challenge test (OCT) was applied to 263 nonreactive cases. OCT was not applied to 15 cases out of 278 nonreactive NST cases, because of placenta previa, abruptio placenta and previous cesarean section. There were 155 cases with negative OCT, 84 cases with positive OCT and 24 cases with equivocal, prolonged or severe variable decelerations. Sensitivity and specificity were for NST 50 and 88% and for OCT 60 and 67%. The positive and negative predictive values were 11 and 98% for NST and 18 and 93% for OCT. It is concluded that the reactive nonstress test is a reliable test for good outcome but a positive oxytocin challenge test is not a reliable test for poor outcome. Additional procedures are necessary such as assessment of fetal growth, doppler velocity waveforms and fetal biophysical profile to avoid unnecessary obstetric interventions and to reach good fetal outcome.