OBJECTIVETo observe Chinese women's cervical physiological changes by transvaginal ultrasound.

METHODS637 normal female volunteers were studied. Cervical length, width and canal width were measured by transvaginal ultrasound. Cervical length multiplied by width was the biggest vertical section area of cervix(cervical area).

RESULTSThe cervical length, width, area and canal width in the menopausal women were significant smaller than that in the un-menopausal women (P < 0.0001). Multinomial logistic regression showed that cervical changes were mainly affected by menopause year, gestation and para. The cervical length, width, area and canal width were negative correlated with menopause year significantly. The cervical and canal width were positive correlated with gestation. The regressive equation was Cervical area (cm2) = 3.69 + 0.23 Gastation -0.16 Menopause year.

CONCLUSIONSCervical physiological changes are mainly affected by the menopause year, gestation and para. The menopause year is the most important factor in the cervical physiological changes.