Bleeding like menstruation at 6 weeks of pregnancy, if it is caused by preeclampsia, there is still a chance for the gestational sac to develop after fetal preservation, if it is caused by embryonic arrest, there is no chance for the gestational sac to develop. 1. Pre-eclampsia: Pre-eclampsia may occur due to infection, external stimulation of the fetus, low progesterone level of the pregnant woman, etc. At this time, if active treatment is carried out to preserve the fetus, the gestational sac can develop normally after successful preservation of the fetus, but if the preservation fails, the gestational sac will not be able to develop normally. 2. Embryonic arrest: if the fetus has chromosomal abnormalities and other diseases, resulting in the embryo stops developing, will also make the gestational sac tissue shedding manifested as abnormal vaginal bleeding, at this time the gestational sac can not continue to develop. When the symptoms of bleeding are found to be heavier after 6 weeks of pregnancy, it is recommended to consult a doctor in time and carry out standardized treatment under the guidance of the doctor to promote the normal development of the gestational sac.