Confirming paternity of an unborn child is done by means of a prenatal paternity test.
Invasive prenatal sampling procedures such as amniocentesis and Chorionic Villus Sampling are considered invasive and carry risks of harming the unborn child and in extreme cases even miscarriage. Both these fetal DNA sampling methods involve a surgeon entering the womb using a needle. The needle can be inserted either through the vagina or through the abdomen.
Non invasive prenatal paternity tests are risk free and easier to have carried out. These tests require a blood sample from the mother and alleged father. Once scientists have this sample, they look for the cell-free fetal DNA in the maternal blood. Thanks to the fetal DNA in the maternal blood stream, scientists can map the unborn child’s genetic markers. As pregnancy progresses the amount of fetal DNA in the maternal peripheral blood stream increases. Before the 10th week, it is not possible to carry out the non invasive prenatal paternity test as quantities of cell free fetal DNA are too small for scientists to provide any conclusive result.