You Have an Amniocentesis?

Should You Have an Amniocentesis?

Amnio can help diagnose chromosomal abnormalities, like Down Syndrome. Find out if you need this test.

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The risk of having a chromosome problem increases as we get older and the noninvasive tests look at 3 of the more common chromosome problems, but don't cover all of the chromosome problems, so a couple may decide since they are at an older age to do an amniocentesis that looks of all of the chromosomes. That's one are the more common indications. Probably the next most common thing is when there is screening test that has been done that puts the person at a high risk, and lastly, if there's an anatomical problem that has detected on ultrasound where it may be due to a genetic problem and so you may choose to test for that particular condition. An amniocentesis involves inserting a needle through the mom's abdomen into the sac of water through the membrane, which was called the amnion and into the amniotic fluid. And so the fluid is withdrawn and then sent to the laboratory to determine the baby's genetics or the baby's carrier type and all 46 chromosomes will be looked up. The doctor will begin by doing an ultrasound to locate the best location where the needle will be placed. The needle tends to be a long-looking needle and that usually makes people worry. What's really important in terms of how they feel is the thickness of the needle. The needle is actually very, very thin. So, it's some-- somewhat like getting your blood drawn. It is a pinch, but it's generally a fairly quick procedure and is not as Comfortable as many people think and the fluid is withdrawn and then needle is removed. We often quote somewhere between 1 and 300 and 1 and 500 complication rate and that can include things from leakage of some fluid, the water bag is being-- needle is being inserted and usually reseals immediately, but sometimes there may be a little bit of leakage even that usually often stops and reseals and is not a problem, but occasionally it continues and doesn't reseal and that can be a problem. So, the concern is-- the main concern is pregnancy loss or miscarriage following the amniocentesis. Amniocentesis actually these days can be sent for a variety of different things. The sort of traditional thing is to send it for chromosomes. There is a rapid test that can look at special 3 chromosomes that we're getting to know well, 13, 18, and 21 and also X and Y chromosome and that special rapid test is sometimes called a FISH test and that-- those can give you results sometimes as soon as 24 hours later. The second part to it is a full chromosome analysis of 4 karyotype and even if you had a FISH test they would the full chromosome analysis also to confirm--