Maternal heart rate pattern: a confounding factor in intrapartum fetal surveillance

Background Maternal tachycardia and accelerations with contractions recorde d on the electronic fetal monitor may confound proper fetal evaluation. Cases Four cases reveal the adverse consequences of failure to recognize th e maternal heart rate on the electronic fetal monitor. One was unexpectedly stillborn, three were severely depressed at birth and one was subsequently handicapped. In one case of twins, the problem arose after the delivery of the first twin. All fetuses presented with normal tracings at the outset o f labor. In three, maternal tachycardia and accelerations with pushing in t he second stage simulated fetal well-being. In one case involving a rupture d uterus, the simultaneously recorded maternal and fetal heart rates interf ered with appreciation of the deteriorating fetus. Conclusion Features of the maternal heart rate during labor may confound in terpretation of the fetal condition, may lead to suboptimal care and outcom e, and may impede understanding of the timing and mechanism of fetal injury .