Role of Non-stress Test and Vibroacoustic Stimulation Test in Prediction of Perinatal Outcome in High-risk Pregnancies

ABSTRACT

Objectives: The aim of the study was to evaluate the fetal well being by non-stress-test (NST) and vibroacoustic stimulationtest (VAST) in high-risk pregnancies, to assess the perinatal outcome, to study the ability of the VAST to convert a false-positive(non-reactive) NST to a reactive one.Materials and Methods: Atotal of 100 pregnant women with >32 weeks gestation having certain high-risk factors were subjectedto NST and if NST came out to be non-reactive, vibroacoustic stimulation was given with artificial larynx. Perinatal outcome wasassessed by various parameters (meconium stained liquor, Apgar score at 5 min, neonatal intensive care units admission). Theresults were analyzed by Chi-square test to find the association between NST, VAST results, and perinatal outcome.Results: It was found that VAST reduced the number of false-positive results by 31%. As compared to NST, VAST had lesssensitivity (78.05% vs. 80.48%), and better specificity (95.08% vs. 83.61%), better positive predictive valve (91.43% vs. 82.35%)in predicting perinatal outcome.Conclusion: The addition of vibroacoustic stimulation to the NST reduced significantly the number of non-reactive tests. NSTwhen reactive does represents a satisfactory indicator for fetal well-being but non-reactive test needs further evaluation beforeany active intervention.