Fetal paternity testing, also known as embryonic paternity testing, refers to the use of genetic techniques to identify the genetically significant father of a fetus. A, the time and method of fetal paternity test In general, the choice of different sample collection methods for paternity testing, the identification time is also different. Specific: 1, amniotic fluid sample collection: usually in the 17-22 weeks of pregnancy, a small amount of amniotic fluid from the maternal abdominal wall as a sample for identification; 2, chorionic villus sample collection: usually in the 11th-14th weeks of pregnancy, a small part of the chorionic membrane cell tissue as a sample for testing; 3, venous blood collection: pregnant women are more than 7 weeks pregnant, under the premise of ensuring the health of the anticoagulation tube to extract the pregnant woman’s arm About 10ml of venous blood for identification. Second, the process of fetal paternity identification in the clinical fetal paternity identification need to follow certain processes: 1, in the identification center appointment identification experts; 2, personally to the identification center site verification of identity, fetal paternity identification sample collection; 3, the sample sent to the laboratory for testing; 4, identification report is generally issued in 5 working days, expedited 6 hours after issuance; non-invasive generally 15 working days for the results. Third, the fetal paternity test precautions for fetal paternity test need to pay attention to matters related to the following: 1, pregnant women need to pay attention to rest before the procedure, if there is a cold, sore throat fever phenomenon can not accept the procedure; 2, the day of the examination can eat breakfast, do not need to fasting blood sampling; 3, chorionic villus biopsy of pregnant women before the examination, the need to do ultrasound and leukocyte cleanliness examination; 4, pregnant women after surgery No bathing on the same day and no sexual life for half a month; 5. Pay attention to adding clothes when going out to avoid catching a cold.