Thanks for addressing this topic and I typed up a very long comment and decided to change it to a post. I've had a really busy week, otherwise I would have written about this sooner. I'm sure Kat will have some thoughts as well. For our new readers, this is a topic near and dear to my heart, as I had a daughter Therese, who died of a fatal birth defect called anencephaly in 2002. Kat also had a daughter, Lucy, with anencephaly. Anencephaly is a fatal neural tube defect easily detected via ultrasound, and it is one of the 4 things for which the Quad screen (also called and AFP or Triple Screen) tests.
Everything for which the Quad screen tests can be detected via ultrasound, the main reason to get the Quad screen is that it is done earlier (and cheaper) than an ultrasound and therefore can alert a couple to a problem sooner, and thereby allow them to terminate the pregnancy sooner :-( Couple this with a high false positive rate for the test, and B-mama is very wise to recommend against this test. Even if your results come back indicating a problem, you then have to wait for the u/s to know if there really is a problem.
Unlike an ultrasound, CVS and Amnio are both very risky and dangerous to the baby. I'm actually not aware of any reason these tests need to be performed, other than to alert a couple to a problem and allow them the option of early termination. If these tests were for some reason medically necessary (in that they could help the baby in some way), an amnio can be done later in the pregnancy when the risk of miscarriage is small (there will be a pre-mature labor risk but that can be handled accordingly and is safer for the baby).
There are actually very few things even a good Obgyn can do prior to the birth of a baby to help that baby (other than setting you up to deliver at the best hospital and choosing a different method of delivery or pregnancy management). Knowing at 14 weeks that the baby has a problem is REALLY not necessary and not at all beneficial for the baby--you can wait until the 20 week u/s to discover problems.
When talking about pre-natal testing, I think it is really important to follow the principle of first do no harm. If the procedure can harm the baby, and the only reason you are getting it done is so that you can know something (not to help the baby in any way), then the test/procedure is immoral and should not be performed.
Second, I think everyone should think long and hard about what they will do with a poor prenatal diagnosis. Most people who plan to love their baby for each day God gives them with that baby don't want to know at 12 weeks that their baby has a fatal birth defect. Even with my history, we try to avoid the 12 week ultrasound to check for anencephaly as I don't think I could bear to hear bad news that early in the pregnancy.
I do, however, believe firmly that at least one ultrasound is best for both the parents and baby. There are conditions, such as placenta previa, that are diagnosed via u/s and necessitate a c-section for the safety of the baby. There is also very little, if any, evidence of harm from ultrasound, so it is a diagnostic tool that is usually always in the best interest of both mother and baby.
Pre-natal testing is obviously a very personal decision that each couple must make. Since the medical profession has values that are usually very different from our own, it is always best to do your own research in this area and ask lots of questions before making any decisions. In my own personal case, I interview potential caregivers and ask them how they would handle me as a patient were I to have a baby with a fatal birth defect. Would they support me in carrying the pregnancy to term? Would they treat me and my baby with respect and dignity? If the caregiver is uncomfortable with these types of questions, they are probably not someone you want caring for you or your baby.
There are a number of resources to help families receiving a poor prenatal diagnosis. Be Not Afraid is a wonderful support group. I would also highly recommend contacting a perinatal hospice.
While I hope and pray that none of our readers ever need these resources, I can say from personal experience that the life of my daughter Therese was a beautiful gift from God. While the wound is still there, deep in my heart, I can now say with confidence that I am unbelievably thankful for Therese. In her brief 9 months she taught her mama how to love, so that someday, I might join her at the feet of Jesus.