Uterine endometrial cavity movement and cervical mucus

Uterine endometrial movements were observed by transvaginal ultrasound during mid- and late follicular phase and luteal phase in 273 cycles (180 spontaneous cycles in 72 patients; 75 clomiphene citrate cycles in 18 patients; 18 gonadotrophin cycles in 11 patients). The percentage of scans with endometrial movements was 74% in the mid-follicular phase, 96% in the late follicular phase and 72% in the luteal phase. Movements of endometrial cavity echo-free space were observed only in the late follicular phase when the cervical mucus was abundant. The direction of these endometrial cavity movements was objective and therefore distinct. The movements were either vertical (cervix-fundus) or horizontal at the fundus, often to and fro, not unidirectional. The endometrial cavity echo-free space content showed a fern-leaf pattern similar to that of cervical mucus. Thus the content might be cervical mucus plus endometrial secretion, and these fluids might be circulating, flushing or communicating via the cervical canal and the Fallopian tubes through these endometrial cavity movements.