Objective: The purpose of this study was to analyze the effects of maternal exercise on fetal heart rate changes to determine prognostic factors for an abnormal trace in labor.
Study design: Two hundred fifty-eight primiparous women who were 33 to 38 weeks of gestation with varying levels of activity were recruited. A symptom-limited incremental exercise test was preformed. Cardiotocography was carried out before and after exercise. Data were analyzed with specialized computer software.
Results: A strenuous level of exercise was achieved. The most common fetal heart rate response seen was tachycardia. The incidence did not vary with the level of fitness, maternal body mass index, or fetal weight. Male fetuses were more prone to fetal distress. A significantly higher proportion of distressed babies were born to older women (P <.0001). The percentage of abnormal traces was equal in the vaginal and caesarean delivery groups.
Conclusion: The results showed no correlation among the incidence of fetal distress, the mode of delivery, and the fetal heart rate changes after exercise.