Imagine you are a woman in a committed relationship. The worst happens and you are raped and become pregnant. What are your options?
Until recently, there was no reliable and safe way to determine paternity in the first trimester. This meant that many women chose to terminate their pregnancy without knowing who the child’s father was. Obviously this is not ideal.
If the woman could determine paternity, she could use that information to help in her decision on whether to terminate the pregnancy. Undoubtedly this would lead to fewer abortions as more women choose to carry their partner’s child to term.
The tricky part of a prenatal paternity test is obviously getting a hold of fetal DNA. One method is amniocentesis. In this procedure, a needle is inserted into the amniotic sac and fluid is withdrawn. This fluid contains a lot of fetal DNA but getting it is not only invasive, it is also normally done somewhere between the 15th and 18th week of pregnancy. This is too late for many women.
Other methods take advantage of the fact that there is a bit of fetal DNA floating around in the plasma of mom’s blood. These tests have the advantage that they are noninvasive and can be done much earlier in pregnancy…sometimes as early as 8 weeks. The disadvantage of the early versions of the test was that they weren’t always as accurate as we’d like.