An abdominal electrocardiogram processing system for determining a fetal heart rate of a fetus in a pregnant woman obtains a combined electrocardiogram measurement of a maternal heart rate and a fetal heart rate. The system then transforms the combined electrocardiogram measurement into a wavelet domain to create a combined electrocardiogram measurement wavelet transform. The system can then remove the maternal heart rate from the combined electrocardiogram measurement wavelet transform. The system then identifies a fetal heart rate from the compensated combined electrocardiogram measurement wavelet transform.