Effect of heat on uterine contractions during normal labor.

The effect of local application of heat on the abdominal wall on uterine activity was evaluated in 15 full-term multiparous women early in the first stage of labor. Cardiotocographic monitoring showed that heat induces a significant increase in uterine activity without causing any abnormal fetal heart changes. The stimulated contractions return back to base line level following removal of heat. The application of heat on the abdominal wall of women in early labor appears to offer a new non-pharmacological modality for the stimulation of uterine activity.