The Challenge of Prenatal Diagnosis

The world of prenatal testing is very confusing, even to parents who are medical professionals. Most of the tests give you statistical odds of your baby having various disorders. The first trimester screening, nuchal translucency test, and second trimester screening all combine to tell you if you are low risk or high risk for these various disorders -- specifically chromosomal disorders such as trisomy 21 (Down syndrome), trisomy 18 (Edwards syndrome), and trisomy 13 (Patau syndrome). For example, my risk from the second trimester screening with Julia came back as 1 in 2400 chance of Down Syndrome and 1 in 880 chance of Edwards syndrome (which she has). My risk was considered low based on these numbers alone. However, I was one of the unusual false negatives with these tests. There are MANY false positives, though. When a mom is given a high risk number for one of these conditions she must make many choices. The first choice is whether to have diagnostic tests performed such as chorionic villous sampling (CVS) or amniocentesis. Only these tests can truly diagnose your unborn child with a chromosomal disorder. The tests are not without risk. The tests carry a risk of miscarriage from 1 in 200-400. (This whole process makes you disdain all statistics.) Obstetricians, perinatologists, and genetic counselors all will STRONGLY encourage anyone at high risk to undergo one of these procedures. And high risk automatically includes any woman age 35 or older. Here are the problems with that advice: 1) the small but real risk of miscarriage and 2) what you will do if you get a positive result for one of the disorders.

In our situation, we originally declined the first and second trimester screening tests, just as we had with or first two pregnancies. We decided instead to have a detailed level 2 ultrasound at 18-20 weeks. When I was 13 weeks pregnant I caught parvovirus or Fifth's Disease that was making the rounds in our local elementary school. This virus is normally not harmful except in pregnancy. I began seeing a perinatologist (high risk OB) for specialized ultrasounds to determine if the baby was showing signs of parvo infection. At 17 weeks I received a level 2 ultrasound which I was told was unremarkable. No parvovirus and no other problems. At 21 weeks I had another level 2 ultrasound where problems were found that were unrelated to a parvovirus infection. The doctor matter of factly told me that he found a heart abnormality called a ventricular septal defect and a dilated left kidney. Because he found two problems, the likelihood of a chromosomal disorder greatly increased. He suggested this was likely Down syndrome and recommended an amniocentesis immediately. I said no. I knew there was a risk of miscarriage and I wanted to confer with Marc. The doctor reminded me that termination was only legal in our state until 24 weeks so I did not have a lot of time to decide. I was reeling from the news and felt appalled at the suggestion and told him I would not terminate. A few weeks later I had another ultrasound where the same doctor told me that my baby did not have a nasal bone. This finding highly correlates with Down syndrome, and he again recommended an amnio that day since our termination options were running out in Maryland. Apparently in New Jersey you have a little more time as my docs suggested we consider going there. In my reading I discovered that more than 90% of babies prenatally diagnosed with Down syndrome are terminated. I was both surprised and very sad. The docs strongly push you in that direction and you feel overwhelmed with fear, worry, and a huge sense of urgency. These same docs who once cared enough for my child to diligently scan for any signs of infection seemingly turned on us and repeatedly suggested termination. We did not pursue an amnio and switched doctors. The news and prognosis seemed to worsen with each scan. Julia's growth sharply declined. Her heart defects were found to be much more serious than a vsd. However, the doctors and ultrasound techs all focused in on the absent nasal bone and so assumed it was Down syndrome. No one thought it would be trisomy 18 instead. Trisomy 18 has an even higher abortion rate and is often defined by docs as "incompatible with life." Too often this phrase is the only thing docs know about t18. (Yes, survival rates are very low, but that label of incompatible with life should cease to apply once the baby is born and living.)

After repeatedly declining amniocentesis, we were followed closely by perinatologists and cardiologists until Julia was born. She received steroid injections to develop her lungs. We were monitored to determine the best time to deliver considering both her cardiac status and her size. I truly don't know if we would have been given the same level of care if we had a prenatal diagnosis of trisomy 18. For that reason I have no regrets about the decisions we made regarding prenatal testing. Many others in our situation do choose an amnio and are able to find supportive docs that will continue to monitor closely. I am just not sure that would have been the case for us given the several perinatologists and cardiologists we saw. Even when we thought we were facing a Down syndrome diagnosis, no one offered us any encouragement or directed us to any support groups or agencies. They were more than willing though to find us a late term abortion clinic. It was so disheartening. Parents in these situations who choose not to terminate still need support! We still need to know that our docs know that our decision to have this baby is a valid decision.

I recently read a blog post that beautifully expresses some of these same sentiments. Please check out this article written by a physician and mom to a precious boy with Down Syndrome. Thank you for reading.