OBJECTIVE To explore the change of vaginal microecosystem of the pregnant women and the related influencing factors so as to provide bases for the prevention and control of flora imbalance.METHODS Totally 400 pregnant women(the pregnancy group)and 400 pregnant women(the delivery group),who were treated in the hospital from Jan to Dec 2012,were enrolled in the study,then the vaginal examination was performed with pH dipstick,the microecosystem test was carried out for the density of vaginal flora,diversity,d...