Prenatal Genetic Testing: There's a lot ot say.

I put off writing this post for quite sometime because of one of the most scary parts of prenatal genetic testing: the false positive.

My doctor advised, and I wanted to have a first round of non-invasive genetic testing. We had a sequential scan. This involved an ultrasound at 11 weeks to measure the baby's nuchal fold (the skin covering the back of the a baby's neck) and a blood test, followed by another blood test at 18 weeks.

The sequential scan looks at the nuchal fold measurement and four hormone and chemical markers in your blood to help pin down the risk a baby might have Down Syndrome (three copies of chromosome 21) Trisomy 18 (again, an extra copy of chromosome 18), a neural tube defect (like spinal bifida) or a congenital heart defect. This gives more information about risks that maternal age alone.

Every pregnant woman has the opportunity to have these tests done. Diabetic women may be counseled more strongly to have the tests because their risk of neural tube and congenital heart defects are already higher.

But, it's important to remember that the tests are completely your choice. If you know that a result will not change how you feel or what you do with a pregnancy, than by all means forgo the testing.

The second blood draw showed higher levels of a hormone called alpha-fetoprotein. This is an indicator of an increased risk of a neural tube defect. The increase was not high, so my risk for having a baby with a problem changed from 1 out of 150 to 1 out of 140 with the result... not too substantial, but definitely worth some tears.

The high AFP value could also indicate a variety of other situations. They ranged from, in the best case, a baby whose growth was a bit stunted, to, in the worst case, a pregnancy had that ended. Interestingly AFP is also a marker for some cancers.

Needless to say getting the call from the genetic councilor was terrifying, and the two week wait until the ultrasound was tense. My doctor reminded me that 1 out of 140 means that 139 babies are just perfect.

The ultrasound went better than well. We got to see the baby's spine and brain. I've never seen anything more lovely. The weird alpha-fetoprotein reading was an anomaly. The baby is growing well.

I have mixed feelings about the genetic screening process. I learned more information about my child's risk of some conditions, but was worried about another, unnecessarily. However, I think, given the increased concern with diabetic pregnancies, I gained some valuable information and I will likely go for it again if I decide to have another child.