What is maternity testing?

We've frequently heard of paternity testing--determining if a specific person is the father of a child. Generally, this type of test is used to establish paternity for child-support payments.

But, how often do we hear of maternity testing? While I was checking on a story my daughter told me about a woman whose biological children matched each other more than they matched her (on DNA testing), I happened on an ad from a company touting maternity testing.

As the company website explains,

The DNA maternity test is useful for individuals who need to determine maternity in a vast number of situations. The most common situations that we see at our laboratory are as follows:

1. IVF: The DNA maternity test is often ordered by mothers who have had a child through in vitro fertilization to ensure that the IVF laboratory had used the correct embryo for implantation.

2. Adoption Reunification: Adult children who were put up for adoption often search for their biological mothers. Once found, most reunified mother child pairs choose to conduct a DNA maternity test to ensure that the correct mother and child have been reunified.

3. Hospital mix ups: After birth, babies often all look very similar. Our laboratory frequently experience situations where hospital staff believe that they may have mixed up the tags on the babies and either the hospital or the children's mother proceed with DNA maternity testing to ensure that a hospital mix up had not occurred.

They go on to describe the difference between a "legal" and a "just-for-information" test:

You have two choices for DNA maternity testing: legal and private. If you require the results of the DNA maternity test for use in court, you must attend an appointment for chain of custody sample collection to ensure court admissibility. However, if you require the results of the test for your own knowledge or to help you to decide what step to take next, the private home DNA maternity test would be the best choice for you because it is fast, discreet, and just as accurate as the legal test.

Hmmmm, now we finally get into the piece I was interested in in the first place: accuracy and reliability. To support their assertion that the test "will conclusively determine whether an alleged mother is the true biological mother of a child", they state:

Our testing laboratory is accredited by both the International Standards Organization (ISO) and the American Association of Blood Banks (AABB). These accreditations provide full guarantee of accurate, straightforward, and reliable results.

ISO is the documentation of practices performed in a business and has to do with management documenting what they do and doing what they document. It is not necessarily a guarantee of accuracy or reliability. The AABB provides standards for the testing and handling of blood, not specifically for DNA testing. It is interesting to me that their list of AABB Accredited Parentage Testing Facilities, updated December 20, 2005, does not include the company offering the maternity test.

So, if you have $260 and want to determine whether X is the mother of Y, you can get one of these tests. I've intentionally not included the company name here, because I'm not into advertising. Also, I've been reading a book lately on the validity of DNA testing--note that I said validity, not accuracy or reliability--and I'm not as gullible as I used to be. More on the statistics of test results in another blog. Meanwhile, I'm still looking for the news story I went after in the first place.

Marie Godfrey, PhD

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