A fetal scalp electrode (FSE) is a medical device employed during labor to directly monitor a baby’s heart rate. This internal monitoring method provides a precise and continuous assessment of the fetal heart rate, which is especially helpful when ensuring the baby’s well-being. By offering real-time data, healthcare providers can make informed decisions about the progression of labor and the baby’s health.
What is a Fetal Scalp Electrode?
A fetal scalp electrode is a small, thin wire with a spiral or hook-like tip. It is carefully placed onto the baby’s scalp to connect the baby to a monitoring system. Once attached, the electrode extends through the birth canal to an external monitor, allowing continuous observation of the baby’s heart activity. This direct connection transmits electrical signals from the baby’s heart, providing a clearer and more consistent signal than external monitoring methods. The FSE is part of a larger system that displays the heart rate tracing for interpretation by the medical team.
Why is it Used?
A fetal scalp electrode is used when external fetal monitoring methods do not provide sufficient or clear information about the baby’s heart rate during labor. External monitors, placed on the mother’s abdomen, can be affected by factors like maternal movement, obesity, or the baby’s position, leading to unreliable readings. An FSE offers a more accurate and continuous tracing in these cases.
Healthcare providers may opt for an FSE if there are concerns about the baby’s heart rate patterns, such as decelerations or reduced variability, which could indicate fetal distress. The precise data helps distinguish between a true concern and a signal artifact, enabling timely intervention. It is also used for continuous monitoring in high-risk pregnancies or during specific stages of labor.
How Does it Work?
A healthcare provider performs the application of a fetal scalp electrode during an internal vaginal examination. Before placement, the membranes must have ruptured, and the cervix needs to be dilated at least 2-3 centimeters. The provider identifies the baby’s presenting part, typically the head, to ensure proper placement.
A specialized introducer tool guides the FSE through the vagina and cervix until the spiral tip contacts the baby’s scalp. The tip is rotated clockwise to attach to the superficial layer of the scalp. This attachment enables the electrode to detect electrical signals directly from the baby’s heart, similar to an electrocardiogram (ECG). These signals transmit to an external monitor, displaying a continuous tracing of the fetal heart rate for interpretation.
Important Considerations
While considered a safe procedure, minor, temporary risks are associated with FSE use. The most common is a small mark or scratch on the baby’s scalp, which heals quickly after birth. In rare instances, there is a minimal risk of infection at the site, mitigated by sterile techniques during insertion. Studies show the risk of scalp injury or cephalohematoma is very low, even if slightly increased with FSE use.
Fetal scalp electrodes are not used in all situations. They are contraindicated if the mother has infections transmittable to the baby through the skin puncture, such as HIV, Hepatitis B or C, or active herpes simplex virus. They are also avoided if there’s a known or suspected fetal bleeding disorder. Healthcare providers weigh these considerations against the benefits of accurate fetal monitoring to determine the most appropriate course of action.