CURRENT INTEREST in the field of human reproduction has created greater demands for accurate evaluation of intrauterine environment. The fetal heart has served as the main indicator of abnormal fetal physiology by evidencing altered myocardial contractility, producing both bradycardia and tachycardia, as well as irregularities in rate. Although one-half century has transpired since the accidental recording of the first fetal heart beat by Cremer in 1906, active interest and progress in this new field of fetal cardiology has been limited to the past decade. With our growing experience and understanding, fetal electrocardiographic (ECG) technique is beginning to emerge as a research tool of wide promise. Based on more than 4,500 fetal ECG case studies, this report will demonstrate the present and future vistas in the study of the fetal heart in the field of human reproduction. Technique A variety of high-sensitivity recording systems are utilized effectively in recording the fetal