In more recent years, testing technology has improved and scientists have discovered that a small amount of the baby's DNA (known as cell-free fetal DNA) is actually present in the mother's bloodstream.
Today, a prenatal DNA test can be performed using a simple blood sample from the mother's arm. It's a much quicker, safer and less invasive way to do a paternity test.
The potential father also has to provide a DNA sample from the inner-cheek, which is compared with the baby's DNA in the testing laboratory.
A DNA test carried out by a reputable company will be entirely accurate. The test will come back with one of two results:
The test effectively gives a yes/no answer.
A prenatal DNA test is only accurate IF a viable DNA sample can be extracted from the mother's blood. If the scientist can't extract a viable sample, the test can be repeated at a later date further into the pregnancy, when the presence of the baby's DNA will be stronger.