Uterine endometrial peristalsis--a transvaginal ultrasound study.

Peristaltic movements of the endometrium were evaluated by serial transvaginal ultrasound throughout 21 spontaneous menstrual cycles, 15 oral contraceptives (OCs) cycles, and 18 in vitro fertilization (IVF) cycles. A score of 0, 1, or 2 was assigned for absent, mild, or strong movements. An average score of 1.5 was obtained at midcycle in spontaneously ovulating women, which was significantly different from early or late follicular (0.36 and 0.5) or luteal (0.4) phase scores. Significant differences were found among the three groups: IVF patients averaged more movements than natural cycle patients, who in turn had a higher incidence than patients taking OCs. Increased peristaltic endometrial movements appear to occur in women around midcycle, probably as an enhancing mechanism for sperm propulsion towards the tubal ostia.