Eleven healthy women with singleton pregnancies between 16 and 28 weeks gestation were continuously exercised, in a graded fashion, by stationary bicycle to a predetermined target heart rate. Before and within 3 minutes after exercise, uterine artery waveforms were identified from a semirecumbent position using a 3.5 MHz continuous-wave Doppler transducer coupled to an Angioscan spectrum analyzer. The ratio of peak systolic to end-diastolic frequency (A/B ratio) was utilized to assess qualitative differences in flow before and after exercise. No statistically significant changes in A/B ratios were noted. This study suggests that nonexhaustive maternal exercise does not compromise uterine artery blood flow in healthy, low-risk pregnant subjects.