The reasons to undergo the test are various including intervention, special needs planning, preparing for lifestyle changes and making a decision to carry your baby to term. Unfortunately, there is a chance of miscarriage with about one in 100 woman miscarrying their baby as a result of the procedure. As with a CVS, experienced doctors may lower this rate so it is worth researching the best doctor to do this procedure.
The amnio test is generally done in the second trimester, between the 14th and 20th weeks. It is not recommended carrying out the procedure any earlier as it is associated with higher rates of miscarriage and a birth defect called talipes. To perform the test, the doctor will use an ultrasound to find a safe location for the amnio needle to enter. The needle will extract a sample of the amniotic fluid. The whole process takes about 45 minutes even though it takes mere moments to extract the sac fluid. The fluid is sent to a lab to be analyzed. The results can take days to weeks and may require patience.
Other side effects, besides the possibility of miscarriage, are cramping, some fluid leakage, and minor irriation near the site where the needle penetrated. These are not concerns unless they continue or get worse.