Which condition contraindicates the use of fetal scalp electrode (FSE)?

The use of a fetal scalp electrode (FSE) is contraindicated in the presence of placenta previa. This condition occurs when the placenta partially or completely covers the cervix, posing a risk of hemorrhage during labor. Inserting a scalp electrode requires an invasive procedure that often involves rupture of the membranes and potential manipulation of the cervix, which can lead to bleeding and complications for both the mother and the fetus. Therefore, using an FSE in this situation can endanger the patient due to the risk of exacerbating the bleeding associated with placenta previa.

In contrast, conditions like active diabetes, normal fetal presentation, and gestational hypertension do not inherently increase the risks associated with the use of an FSE in the same manner. While careful monitoring is necessary in those conditions, they do not present the same level of immediate risk to mother and fetus as placenta previa does.