What is Amniocentesis or Amnio?


Minister's of Penmai
May 21, 2011
What is amniocentesis?

Amniocentesis is a prenatal test that allows your healthcare practitioner to gather information about your baby's health from a sample of your amniotic fluid. This is the fluid that surrounds your baby in the uterus.
The most common reason to have an "amnio" is to determine whether a baby has certain genetic disorders or a chromosomal abnormality, such asDown syndrome. Amniocentesis (or another procedure, called chorionic villus sampling (CVS)can diagnose these problems in the womb.Amniocentesis is usually done when a woman is between 15 and 20 weeks pregnant. Though all women should be offered the option of having an amnio, women who choose to have this test are primarily those at increased risk for genetic and chromosomal problems, in part because the test is invasive and carries a small risk of miscarriage.Here are a few other reasons that amniocentesis may be done:
  • To assess the maturity of your baby's lungs when considering an early delivery for medical reasons (unless it's clear the baby needs to be delivered immediately regardless of lung maturity
  • To diagnose or rule out a uterine infection
  • To check on the well-being of your baby if you have a blood sensitization, such as Rh sensitization. This is a complex condition that can occur if your blood is a different type than your baby's. (Note: Obstetricians are increasingly using Doppler ultrasound for this purpose instead of amnio.)

How are "Amnio" Done?

  • Before you have your amnio, you'll have an ultrasound to measure your baby and check his basic anatomy. (Some testing centers do this when you come in for your amnio, while others do it in advance.)
  • For the amnio itself, you'll lie on an examining table and your belly will be cleaned with alcohol or an iodine solution.
  • Ultrasound is used to pinpoint a pocket of amniotic fluid a safe distance from both the baby and the placenta. This part can take up to 20 minutes.
  • Then, under continuous ultrasound guidance, the doctor will insert a long, thin, hollow needle through your abdominal wall and into the sac of fluid around your baby.
  • She'll withdraw a small amount of amniotic fluid — about an ounce, or two tablespoons — and then remove the needle.
  • Withdrawing the fluid can take a few minutes but usually takes less than 30 seconds. Your baby will make more fluid to replace what's taken out.
  • You may feel some cramping, pinching, or pressure during the procedure — or you may feel no discomfort at all. The amount of discomfort or pain varies among women and even from one pregnancy to the next.
  • You may choose to have your abdomen numbed first with a local anesthetic, but the pain from the anesthesia injection is likely to be worse than that of the amnio itself, and most moms-to-be decide that one needle is enough.
  • Afterward, your doctor may use an external fetal monitor to listen to the baby's heartbeat for reassurance.
  • Note: If your blood is Rh-negative, you'll need a shot of Rh immune globulin after amniocentesis unless the baby's father is Rh-negative as well. (Your baby's blood may mix with yours during the procedure and it may not be compatible.)
What happens after the procedure?
You'll need to take it easy for the rest of the day, so arrange for someone to drive you home. Avoid any heavy lifting, intercourse, and air travel for the next two to three days.You may have some minor cramping for a day or so. If you have significant cramping or vaginal spotting, or you're leaking amniotic fluid, call your practitioner immediately. They could be signs of impending miscarriage. Also call right away if you have a fever, which could be a sign of an infection.

source: Babycenter​
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