Prenatal Testing
All the prenatal tests
This website http://kidshealth.org/parent/system/medical/prenatal_tests.html
is an excellent discussion of all the different prenatal tests that are done,
including those performed to determine the mother’s health condition (e.g.
blood tests, urine tests, glucose screening, and so on), the baby’s condition,
and tests for congenital abnormalities (more on these tests below.)
Prenatal tests which screen for risk of abnormalities, or detect
abnormalities. These include: ultrasound, AFP testing (a.k.a. Triple Screen),
amniocentesis, and chorionic villus sampling (CVS). The
Some notes about these tests:
Screening tests (e.g. AFP) can only indicate what the potential chance is of your
baby having a problem. If the risk is high enough, then you will go on for more
testing (like CVS or amnio). These tests have a high false positive rate: there
is a 5% chance of a positive result, but only 1 in 30 of those babies actually
have a problem. Thus, this test can cause a great deal of emotional stress in
families (and cause them to go on to further un-needed testing, which carries
risks for baby.) There’s also a risk of false negatives: even if nothing shows
up on this test, there’s a chance of problems with the baby, thus causing false
confidence in the parents which may lead to more stress than if they’d never
been tested.
Amniocentesis and CVS: These tests carry risks of miscarriage (from .5 – 1.5%) Also,
there is an undeniable emotional stress of uncertainty while waiting for test
results (3 days to 2 weeks for CVS, a month for amnio results). The risk of
false negatives is about 3%. Also, even if you receive a correct diagnosis, the
tests cannot tell you whether your child will have a mild condition or severe
problems.
Before beginning this testing, it is important for you (and
your partner) to ask yourselves: “If these results show that our baby has a
problem, what will we do about that?” Most prenatal tests are designed to find
things that can’t be fixed (congenital anomalies).
Thus, if testing results indicate a problem, parents then need to
choose whether to terminate the pregnancy, or whether to continue the
pregnancy, and begin preparations to care for a special needs child. Some
people feel like they do not want to face this choice, and would feel more
comfortable just waiting until the baby is born, and then dealing with any
problems that may come up; thus they choose not to do the testing.
Compiled by Janelle Durham, 2002.