False reactive nonstress tests in postterm pregnancies

Abstract

One hundred twenty-five postterm patients with reactive nonstress tests (NSTs) were studied between January, 1978, and September, 1979. Ten poor outcomes occurred for a false reactive rate of 8%. Included were four antepartum deaths, one neonatal death, one brain-damaged infant, and four cases of fetal distress on admission. The NST was misleading by giving false reassurance of fetal well-being. The major mechanism causing acute fetal distress was cord compression, which frequently occurred with uteroplacental insufficiency, but occasionally without it. The oxytocin challenge test (OCT) was useful in unmasking problems of cord compression and may be a more sensitive indicator of fetal well-being and distress in the postterm patient.