Quote:
Originally Posted by
kitchensqueen 
A couple of things to consider about amnio -
- False positives are fairly common (sorry I don't have the statistical numbers handy).
- Most of the genetic disorders cannot be treated or addressed in utero - if you plan to keep your baby if something shows up this can prevent or make it difficult to bond with your child if you're upset about the results. Or it can help you prepare for a special-needs arrival - it can go either way for you.
- There is a risk of damage to the child and miscarriage (1 in 200 according to Dr. Sears).
If you don't have a family history of any of the genetic disorders it tests for, and you wouldn't abort the baby if something were wrong, you really don't need to get the test.
False positives for WHAT are fairly common with amnio? For chromosome diagnosis, it is extremely accurate. If you have a full karyotype done, the chances of them coming up with a diagnosis like Down Syndrome and it not actually being Down Syndrome is vanishingly small. False negatives, where it misses small defects or genetic problems that it is not testing for, is more possible. But still, it is as accurate as anything likely to be done after a baby was born.
The blood test+ultrasound screenings are just that, screenings, and most people who come up as requiring further study do not turn out to have problems. But amnio is considered diagnostic, and the risks of a false positive are extremely low. With our CVS, the sample failed to grow at all, but our amnio did just fine. You have more risk of "no result" than "result that is not accurate", with both tests.
The risk of damage to baby and miscarraige at 20+ weeks is quite small, far less than 1 in 200, though this is ALWAYS a practitioner-dependent number. My perinatologist said his personal stats are less than 1 in 1000 loss for amnio and 1 in 500 for CVS, because he's very careful and conservative about how he does them. I can go into specifics, but the risks at 20 weeks are much, much lower than Dr. Sears would imply. CVS or amnio done too early can be quite risky. Done by a practitioner with little experience, they can be even more risky. Done by a competent doc, late enough in pregnancy, the risks are far lower. The overall background risk of loss is higher than the risk of loss from amnio or CVS.
A family history of genetic disorders is irrelevant when it comes to the kinds of testing that they're usually looking for for someone over 36 years old. I have no history of chromosome disorders, but at age 33 had a child with a rare mutation that deleted a chunk of her 4th chromosome. Family history had jack all to do with it.
All that said...
When it comes down to it, the decision to test or not boils down to a couple of factors:
1. If you got a diagnosis that would imply severe, lifelong special needs, would you continue the pregnancy or not? With my second child, the answer was, "There is no circumstance under which I would abort." With my third child, the one I'm pregnant with now, the answer was, "I cannot do another highly special needs child, and would rather abort than continue a pregnancy where I knew the child would have anything like my second child's level of special needs."
2. If your child did end up having a chromosome disorder, and was born and had a problem that could have been mitigated by immediate treatment, and you hadn't gotten the testing, would you be upset at yourself for not doing the testing? In my case, with my second child, the answer was NO. Not only that, but because we did not know in advance, I birthed at home. Because I birthed at home, I was not c-sectioned (I would have been in the hospital and can elaborate if anyone needs me to) and she did not go into the NICU for feeding issues. We managed her issues at home, I breastfeed her for 2 1/2 years, and she's currently doing far better than anyone ever thought she might, and the chances are high that things would have been WORSE with immediate medical intervention. There is a perception that most "special" babies need instant treatment and will be worse off if they do not get it within minutes of birth. In reality, delays in treatment are often not that significant, and even with the rare disorders, there are few conditions where advanced knowledge truly changes the end result. Spina bifida is one counterexample, but spina bifida of the sort that will do better with special delivery can usually be diagnosed via ultrasound at 20+ weeks.
3. How much anxiety would it cause you to not get the test? For me, continuing a pregnancy past 13 weeks not knowing (because our CVS sample failed to grow) was a nightmare every day until we got our answer at 17-ish weeks. Had I not tested, I would have had anxiety every single minute of every single day through delivery and been jumpy until well into the first couple months of my child's life. Another friend who got pregnant in her forties described exactly this scenario...declining the testing despite "advanced maternal age" (Older than I am now, at 39) and having crying jags about the fear of a serious problem until the baby was born healthy. But once I knew things were okay, I stopped having panic attacks and anxiety and flashbacks to my daughter's postpartum, and was able to accept the pregnancy with a more open heart. With my second, the very idea of testing was anxiety inducing, and I was very happy to go through the pregnancy not knowing, and to this day I'm glad I didn't know ahead of time.
I love my daughter. I don't regret having her. But that doesn't mean that at this stage of my life and in the health I'm in, I could deal with another babyhood like hers was. It was insanely, mind bogglingly hard. I had weeks, months where I barely slept due to her feeding issues, pumping, anxiety... I cannot tell you how many doctors we've seen or how many professionals have shrugged their shoulders and blown us off. I've often felt like her doctor, her researcher, her therapist, to the point where sometimes I don't feel like her mother. The stress of her first few years of life quite literally nearly killed me. When I say I cannot do that I again, I quite literally mean I'd rather die that go through that process another time if I had another choice. I don't wish I had it to go back and do over again. I don't wish she'd never been born. But it was actually a condition of even trying to get pregnant for both my husband and me, that we do prenatal testing and strongly consider abortion if there was another major genetic/chromosome defect. There's a reason there's such a big gap between my kids...
There are no guarantees. There are plenty of ways the process can go wrong that amnio can't test for. But knowing that my boy's chromosomes are normal, that whatever else happens, he's not starting out with that stacked against him... it makes it a little easier to trust the process.
I've been pregnant four times with my husband. Two of those pregnancies were early losses. One was my daughter and her chromosome issue. I had no room to be cavalier about "Oh, it's probably going to be fine."
