Jen's Pregnancy Blog

Two weeks after that, at about 10 weeks gestation, I had another test. This was a prenatal test to measure the thickness of the back of Baby’s neck. Taken with a blood test, the results can tell you how likely it is that you will have a baby with Trisomal 18/13 and Downs Syndrome. Trisomal 18/13 is a condition where the baby has either gotten an extra copy of chromosome 18 or 13. This condition, in 90% of cases, is lethal for the baby; most die before or right at birth. I am happy to report that the test results are back and there is very little likelihood that our Baby has either condition. In fact, the nurse was very happy with the results when she called me.

Now, understand I didn’t expect anything to be “wrong.” I am under 35 years of age and am relatively healthy. Brian & I felt a bit of pressure at our first appointment to do some prenatal testing because of our genetic backgrounds. It had everything to do with our dwarfism since neither of us has any other conditions in our family history that would put us at risk. We met with the staff geneticist at our first appointment and determined that our risks for many genetic issues (other than our dwarfism) was extremely low.

I will not consent to an amniocentesis (unless a new situation presents itself that actually warrants such a risky procedure). I don’t need to know right now whether or not Baby has dwarfism; it wouldn’t change anything about what’s happening. And my doctor and I agree that we will be able to determine that later in the pregnancy through ultrasound. So, we wait.

Let me try to quickly explain the genetics between Brian & I. Brian’s dwarfism (diastrophic) is a recessively inherited form of dwarfism. Both of his parents are carriers but neither of them have it. It takes two recessive matching genes for that form of dwarfism to show up. Since it is highly unlikely that I carry that form of dwarfism, our child will be a carrier for diastrophic, but will not have it.

My form of dwarfism (SED) was a dominant genetic mutation. That means that no one in my family before me had it or was a carrier for it. A simple mistake was made as my chromosomes were splitting during my creation. One of those genes didn’t get copied exactly and now I have SED. Because it is a dominant gene, it only takes one gene for our Baby to have SED. So there is a 50/50 chance that our Baby will inherit the SED gene from me.