Endometrial wave-like activity in the non-pregnant uterus.

The non-pregnant uterus shows wave-like activity throughout the menstrual cycle. This uterine activity was first detected using intra-uterine pressure recordings. The use of ultrasound has made it possible to study the movements of the uterus in a non-invasive manner. Throughout the menstrual cycle, several wavelike activity patterns have been described; these patterns change throughout the menstrual cycle and are governed by steroid hormones. An adequate wave pattern seems to be related to successful reproduction in spontaneous cycles and assisted reproduction. Further insight into the phenomenon of endometrial wave-like activity might offer an opportunity to correct abnormal wave patterns and thereby improve pregnancy rates.