Fetal magnetocardiography (fMCG)

Fetal magnetocardiography (fMCG) is a test performed during pregnancy to evaluate the electrical activity of an unborn baby’s heart. fMCG is available at only a few programs in the country.

What is fetal magnetocardiography (fMCG)?

While echocardiography (echo) is the most common way to detect arrhythmias, it is limited when it comes to detecting fetal arrhythmias. A normal surface echo can detect abnormalities in a heart’s electrical activity, but because a fetus is in an “insulated cocoon,” no electrical signals escape.

Fetal magnetocardiography, a relatively new and groundbreaking tool, overcomes this challenge by recording the natural magnetic signals that come from the fetal heart rhythm. This safe, non-invasive and FDA-approved procedure can potentially improve diagnosis and guide treatment for heart arrhythmias before the baby is even born. Unlike an MRI, fMCG does not produce ultrasound or magnetic energies.

What problems can fMCG diagnose?

One of the leaders in fMCG research, Janette F. Strasburger, MD, a received several National Institutes of Health grants to conduct research in this area, most recently a $2.4 million R01 grant to assess the role of “hidden” fetal arrhythmia in fetal death. Read our highlight in Connexions magazine.

How is an fMCG performed?

The test may be done in a cardiologist's office, in a clinic, at a hospital or medical center as an outpatient, or as an inpatient in a medical facility.
• An ultrasound machine will be used first. This will determine the position of your baby’s heart.
• During the test, the technician the fMCG recording device will be placed over the baby’s heart and will rest lightly on your stomach.
• Each fMCG recording will be conducted in 10-minute time frames, with the entire appointment taking one to three hours. You can take breaks as needed.