It is possible to do paternity testing during pregnancy. The testing methods include venous blood sample testing, fetal chorionic villus tissue testing, and fetal amniotic fluid sample testing. 1. Venous blood sample testing: The peripheral blood of a pregnant woman can be taken around 7 weeks of pregnancy for paternity testing. This test is non-invasive and simple. 2. Fetal chorionic villus tissue test: Pregnant women can undergo a puncture test of the chorionic villus when they are 12-14 weeks pregnant. By extracting a small amount of chorionic villus tissue, it is possible to do a DNA material extraction test. 3. Fetal amniotic fluid sample testing: When pregnant women are 16-21 weeks pregnant, amniotic fluid can be extracted with the assistance of ultrasound, so as to conduct paternity testing. For paternity testing during pregnancy, it is recommended to go to the genetics department of a regular hospital and consult a professional doctor. Women should pay attention to rest during pregnancy, and at the same time should relax, avoid tension, anxiety, any discomfort should be timely to the hospital, the doctor to clarify the diagnosis, and cooperate with the doctor to deal with the symptoms.