Instantaneous fetal heart rate monitoring by electromagnetic methods

Fetal magnetocardiography (FMCG) is a new complementary external method for accurate antepartal FHR recording. Because of the low magnetic noise level required it is not yet suitable for routine hospital use. Fifty-six simultaneous FMCG and external FECG measurements were made in order to compare these methods for instantaneous FHR recording. The error of the FHR value obtained with the instrumentation described is less than 1 per cent. Our results show that FMCG can be used for FHR processing from week 30 of gestation until term. Thirty-five of the measurements were done during this period. From these, a readable FHR curve was obtained in 21 cases with FMCG and in 12 cases with external FECG. The maternal complexes were always present in the FECG, but in only 15 of the recorded FMCG's.