Fetal DNA Screen

Fetal DNA Screen

Pregnant families are now presented with more screening options than ever before. One relatively recent screening tool is a blood test that can screen for chromosomal abnormalities. This test can also determine things like a baby sex and RH factor, though the company asks that these are not to be the only factors in choosing such a screen. A blood sample is taken from mom, and can draw fetal DNA from that sample for analysis (Amazing!) Information from that sample can give a probability of having a baby with a genetic disorder. It screens for a higher number of disorders than previous tests, and has higher accuracy. Also this screen can be offered as early as 10 weeks, and is considered non-invasive and low-risk.

This screening tool is offered only to a small group of women at this time – women who are over 35, who have a personal or family history of chromosomal disorders, or who have had a screening in the pregnancy via First Screen, Quad Screen, or ultrasound that suggests presence of a chromosomal disorder. Any result that indicates a chromosomal difference is to be followed up with further genetic counseling and diagnostic testing or further screening, per family desires.  Families who choose to do this screen often state that they feel if they had a positive screen, it would give them the time to prepare for what would have been an unanticipated outcome, and to begin to create community and support for having a child who may have special needs.

The test sounds fairly straightforward, but there is a fair amount of controversy regarding such a screening tool, especially in the out of hospital birth community. You might have noticed that throughout the information on this, it is referred to as a screening test. This is not a diagnostic test, no matter how accurate the results are compared to other screening tests. You may have a positive result (a result indicating your baby has a chromosomal disorder) that is not accurate or true, as well as potential for a negative result (indicating there are no chromosomal abnormalities) when there are. While the majority of results will indicate a baby without abnormalities, those families who have a positive result can experience a lot of grief and stress related to this result, especially when the result is not accurate.

What I find most fascinating about this test is that when we are pregnant, we carry our baby’s cells in our bodies. More than close to our hearts! I’d love to hear your thoughts, what do you think? Have you chosen to have genetic screening, and why? How much can we know about our babies before they arrive? Interested in reading more?  Want to hear more? Here is a link to the recent article on NPR.

By AnnMarie Rian Wanzeck

1 Comment
  • Marlene
    Posted at 02:48h, 21 May Reply

    I have had a positive test result for trisomy 21 from the matetniT21 test. The genetic counselor told us to have no hope that our little girl will be normal. She is saying that they found an extra chromosome in my blood and it can’t be me because I don’t have Down syndrome so it is my baby. Not once did she say this is screening test. According to her our baby will be born with it. They sent us pamphlets in the mail for Down syndrome and told us to call support groups. I still have hope that our little girl will be healthy but we are so upset with the results.

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