[The effect of maternal exercise on the fetal heart rate]

The effect of maternal exercise (the two-step test of Master) on the fetus was studied in 28 pregnant women. These subjects consisted of 5 cardiac cases, 5 cases with IUGR, 5 cases with preeclampsia and 13 normal pregnant women. Overt deceleration of the FHR was found after exercise only in 3 cardiac cases whose FHR tracings had been normal before. Slight changes such as a small rise or a small fall in FHR after exercise were seen in 4 of 7 cases who had shown decelerations in FHR before, and in a normal case. Fetal tachycardia appeared in 2 normal cases immediately before exercise; in one case the FHR tracing appeared not to be influenced by exercise; in the other case it rested at the normal baseline level after exercise. In most cases the amplitude of baseline variability remained unchanged or decreased after exercise. The severity of deceleration before exercise did not correlate well with the results of the exercise test. The exercise test did not reveal any new patients who might have placental insufficiency, suggesting that this procedure may not be warranted for evaluating a patient with placental insufficiency. Fetal response to exercise, however, may disclose a maternal hemodynamic problem. The exercise test with FHR monitoring should be recommended to a patient with heart disease.