Assessment of intra-uterine growth retardation by fetal magnetocardiography

Fetal magnetocardiography allows the noninvasive registration of the prenatal cardiac electrophysiological signal. The good signal-to-noise characteristics of most biomagnetometers combined with adequate signal processing techniques generally permit the identification of the fetal deand repolarization onsets and offsets to an accuracy of 1 ms. The P wave, QRS complex and sometimes the T wave can thus be determined in the second and third trimester of pregnancy. A number of studies have shown that fetal cardiac time intervals change systematically during pregnancy [1-5] (see also Fig.1). It is presumed that these changes are primarily due to fetal growth and maturation. It follows that in pregnancies in which the fetal growth is slowed, this might be reflected in the duration of the cardiac time intervals. The aim of this study was to examine the duration of the cardiac time intervals, as assessed by fetal magnetocardiography, in intrauterine growth retardation (IUGR). The intervals of a large group of normal singleton pregnancies were used as a control. The intervals obtained from several twin fetuses were used to examine a particular group at risk.