The most common explanation for fetal tachycardia is -

Fetal tachycardia is defined as a baseline hea rate greater than 160 bpm. The most common explanation for fetal tachycardia is maternal fever from chorioamnionitis, although fever from any source can increase baseline fetal hea rate. Other causes of fetal tachycardia include fetal compromise, cardiac arrhythmias, and maternal administration of parasympathetic(atropine) or sympathomimetic (terbutaline) drugs.