Abstract: Mid-pregnancy vaginal bleeding is the common obstetric emergency， for its causes are complicated including placenta factors, cervix factors, corpus factors, vagina factors, pertinent disease of gravidity and whole body disease etc and the gestational age is small it often causes difficulties in clinical treatment. People with mid-pregnancy vaginal bleeding whose preterm delivery rate, cesarean section rate, perinatal mortality is significantly increased, and the average gestational age at delivery, average perinatal birth weight is decreased in varied degree. To compare the mid-pregnancy vaginal bleeding patients who had abnormal ultrasound findings and no abnormal ultrasound findings. The former appears more significantly increased risk of adverse outcomes. So ultrasonography can be a powerful tool to predict the outcome of mid-pregnancy vaginal bleeding.

Key words: Pregnancy trimester, second, Vaginal, Postpartum hemorrhage, Pathology, Pregnancy outcome