Women who are at least 9 weeks pregnant can receive a prenatal paternity test. A Prenatal paternity tests can be done between a possible father and his potential unborn child with zero risks to the fetus. This is one of the earlier ways of identifying the relationship between a potential father and child. Prenatal paternity testing is non-invasive and 100% safe for both the mother and the unborn child. This is done by a simple blood test, with no needles going near the fetus.