Predictive value of antepartum non-stress test in multiple pregnancies

Twenty-seven sets of twins in the last trimester of pregnancy underwent 122 antepartum non-stress tests (NST). The NSTs were evaluated by a cardiotocography score. The last test was performed less than one week antepartum. Fifty fetuses had a normal NST, 13 were small-for-gestational age, but only one of these required intensive neonatal care. Four fetuses had one or more pathological NSTs; all 4 were SGA, and these required intensive neonatal care. The pathological variables in the cardiotocograms were reduced variability, absence of spontaneous accelerations, and (late) decelerations. There was no perinatal mortality. Pathological NST was associated with a statistically significantly increased rate of neonatal morbidity, reduced intra-uterine growth and a low one minute Apgar score. For the evaluation of retarded intra-uterine growth, the predictive value of a normal NST was 95.7%, and the predictive value of a pathological NST was 75.0%. The assessment of fetal wellbeing in multiple pregnancy by non-stressed antepartum cardiotocography is of clinical value and seems to be a better predictor of perinatal morbidity than are serial estriol analyses and serial biparietal diameter measurements.