In the first trimester paternity testing involves an invasive procedure called CVS or chorionic villus sampling. Paternity testing can be completed as early as the 10-12th week of pregnancy if the mother is willing to have in vitro testing completed. The in vitro test, Chorionic Villus Sampling requires the mother undergo a procedure involving a needle being inserted through the cervix via the vagina or the abdomen in order to pull a sample of the chorionic villi from the uterus. These villi have the same genetic code as the baby and will be used to match the DNA to that of the potential father.
Amniocentesis can also be used in paternity testing between the 14th and 20th week of pregnancy. This procedure involves a needle being inserted into the uterus and eventually into the amniotic sac for a fluid draw. The procedure is commonly used to test the lung maturation in pregnancies where the baby may be born premature.
Aside from the prenatal testing, there are four postnatal tests that can be completed as soon as baby is born. These tests are blood collection, cheek swab, cord blood testing and other DNA samples like hair or semen.
In some cases, the court system will need to grant approval for the paternity testing to be completed if they are involved in the paternity hearing or case. If this is the condition, the mother will need to wait for the court order to complete the paternity testing. Voluntary paternity testing does not require a court order to be completed. The safest forms of paternity testing are any of the four postnatal tests.