A little bit of bleeding in 12 weeks of pregnancy may be caused by pre-eclampsia, cervical polyps, fetal arrest and other reasons. 1. Pre-eclampsia: 12 weeks pregnant by frequent sexual activity, heavy physical labor, fetal dysplasia and other factors, may lead to the placenta and the wall of the uterus between the capillary rupture bleeding, the first ultrasound to understand the development of the fetus uterus, and then consider whether to be treated or terminated the pregnancy treatment, more attention to bed rest during the period of birth control, and, if necessary, with progesterone, vitamin E, and other medications to protect the fetus. 2. Cervical polyps: If a pregnant woman has cervical polyps, the polyps are rich in capillaries, capillary rupture will cause bleeding, according to the individual situation can be observed or polyp removal surgery to remove the lesion. 3. Fetal arrest: 12 weeks of pregnancy due to poor embryo quality, chromosomal abnormalities, maternal viral infections and other factors leading to fetal arrest, the fetus in the uterus to stop the development of some of the tissues stripped off will cause bleeding, go to the hospital to do ultrasound to determine that the fetal arrest, you can not continue to carry on the pregnancy, we must use misoprostol tablets, mifepristone tablets and other drugs in a timely manner induced abortion or termination of pregnancy with scraping surgery.