The use and important role of artificial larynx on Non stress Test.

Keimyung Medical Journal 1989;8(1):87-96.

NST(산전검사)시 Acoustic Vibrator (artificial larynx) 의 이용과 그 중요성

윤성도; 서영욱

Abstract

The close association between human fetal heart rate accelerations and fetal health has been largely documented. However; because healthy fetuses may be at rest as long as 80 minutes; there has been a high false positive rate for NST performed over 20 or 40 minutes. Artificial larynx has been used to increase the reactivity of human fetuses. Authors analysed the effects of artificial larynx on NST on 84 high risk pregnancies in various gestational ages (28-43 wks) for 9 months (1988’ 6-1989. 2) at obstetric service. The indications for NST were mostly suspected postterm; PROM; and pregnancy induced hypertension in orders. The reactive NST rate was 73.8%. The induction rate of fetal heart acceleration was 56.0%; but it was increased to 95.3% when the artifiial larynx was applied together. 2 cases of spontaneous FHR decelerations were found during NST. The rate of cesarean section in reactive NST group was 6.4%; and that in non-reactive NST was 8.7%. (Key words; artificial larynx; false positive rate; Spontaneous FHR delelerations)