Eighteen pregnant women affected with fetal growth retardation in the last trimester were exercised. The mean maternal heart rate increased significantly from 140 beats per minute (bpm) (120-188 bpm) at rest to 172 bpm (163- 178 bpm) after exercise. The mean exercise intensity was 65% (56-85%) of submaximal exercise. Maternal systolic blood pressure rose significantly from a mean of 116 mmHg (100-140 mmHg) to 159 mmHg (120-190 mmHg) and the diastolic blood pressure rose significantly from a mean of 72 mmHg (55-110 mmHg) to 90 mmHg (80-110 mmHg). The umbilical artery pulsatility index (PI), after an initial decrease, showed a 12% rise at 8, 16 and 30 minutes of recovery. Patients who smoked had a significantly higher umbilical artery PI before and after exercise. Less active Patients had a higher PI before and after exercise than active ones. Infants weighing 1.9-2.5 kg at birth had a higher PI than those weighing 2.6-3.3 kg. Male fetuses had a significantly higher PI than female fetuses.