The relationship of the transabdominal fetal electrocardiogram (FECG) to fetal development will be investigated from very early gestation through parturition in experimental goats. A quantitative fetal ECG will be obtained, despite the presence of corrupting 'noise,' by a unique computer processing technique. This technique, real-time adaptive filtering, will extend the observation range of the FECG to early gestation by its de-noising properties, without introducing the distortion resulting from the usual band-pass filtering or signal- averaging methods. It is possible with this technique to observe and measure all features of the FECG (amplitudes, durations and intervals of the P, QRS and T waves, as well as vector components) under severe conditions where the peak-to-peak random noise is three times the amplitude of the fetal QRS complex. The presence of a high amplitude maternal ECG does not alter this performance. The sensitivity of the adaptive filtering method will first be tested by observing how early in gestation a fully quantitatable FECG can be acquired. Next, using a vector dipole lead system, the developmental features of the transabdominal FECG will be correlated with gestational age and stage of fetal development, including myocardial mass, heart chamber volume, and amniotic fluid volume. As the FECG and related computer processing methods are non- invasive, the results of this project could then be applied to future clinical studies for prenatal health care applications.