Biochemical pregnancies usually do not have visible expulsion of the gestational sac. Biochemical pregnancy refers to a short period of time after the union of sperm and egg, the development of a short period of time soon stops, can be detected with the use of pregnancy test paper chorionic gonadotropin, but clinically there is no manifestation of pregnancy. Since the fertilized egg does not bed down on the endometrium and therefore does not form a gestational sac, even biochemical pregnancies usually do not have a visible gestational sac to be expelled. Biochemical pregnancy is due to chromosomal abnormalities, genetic variations, sperm and egg quality abnormalities and other reasons that lead to the failure of the fertilized egg to bed, because the pregnant egg did not develop to the degree of ultrasound visibility, so it will be discharged with the lining of the uterus out of the body and miscarriage. When the patient biochemical pregnancy a week after the best is to go to the hospital to do a B ultrasound examination to determine whether the bruises are drained, if there are uncomfortable symptoms also need to consult a doctor in a timely manner to check, clear the cause of the standardized treatment.