The fetal heart response to static antenatal exercises in the supine position

Continuous fetal heart rate traces were made in twenty-six low risk patients during static maternal exercises in the supine position, as prescribed in a hospital's antenatal education programme. Prior to exercise, fetal heart rate abnormalities were present in four patients. Three of these had an abnormal fetal outcome. During the exercises a further eight cases had reductions in fetal heart rate, variability or reactivity. An abnormal fetal outcome was recorded in two of these cases. The findings indicate uncertainty about the safety of antenatal exercises in the supine position in late pregnancy and, until further studies are available, it is prudent to advocate the practice of all antenatal exercises in a tilted position, and not at all where fetal compromise is suspected.