Variable decelerations in reactive nonstress tests with decreased amniotic fluid index predict fetal compromise

A total of 3158 patients at greater than or equal to 34 weeks' gestation undergoing nonstress tests and amniotic fluid index determinations were divided into six groups according to the amniotic fluid index and the nature of the decelerations. Fetuses with antepartum decelerations had statistically significantly increased incidences of intrapartum decelerations and operative deliveries because of intrapartum "distress," regardless of the amniotic fluid index. They also had significantly increased rates of neonatal acidosis and low Apgar scores when there were "severe" decelerations and an amniotic fluid index less than 5 in the antepartum period. Thus spontaneous decelerations in reactive nonstress tests with an amniotic fluid index less than 5 may predict fetal compromise.