Amniocentesis

Amniocentesis

Learn more about why mothers over 35 choose amnio and the possible risks from this prenatal test.

Amniocentesis has been used in the United States since the mid-1970’s. Once routinely offered to all women over 35, now amniocentesis is used more judiciously as a follow-up for other prenatal screening tools such as AFP or CVS. What are some questions if you are considering an amnio?

When is the amniocentesis offered?

Amniocentesis, often called “amnio” is offered around 14-18 weeks of pregnancy.

What does the amniocentesis test for?

Several hundred genetic or chromosomal defects or other disorders can be detected with about 98% accuracy including Down Syndrome, spina bifida, Tay-Sachs, hemophilia, and various other chromosomal problems. It does not indicate some physical problems such as a heart defect.

How is amniocentesis performed?

Your obstetrician or specialist such as a perinatologist will take a sample (about 1 ounce) of your amniotic fluid by inserting a needle through your abdomen and into your uterus. It can be done with local anesthetic and in the doctor’s office. Ultrasound is required for accurate placement. Results are available in about 3 weeks.

Are there risks to amniocentesis?

The downside to amnio is that there is about a 1 in 200-400 risk of a miscarriage or a 1/1000 risk of a uterine infection which can lead to a miscarriage. For those reasons, this is not a test for every woman so you should consult with your provider to see if you are a candidate for this test. Even though results are accurate as early as 11 weeks gestation, there is an additional increased risk of miscarriage if done this early.

In fact, the Cochrane Library (a review board that compiles research studies in order to come up with a recommendation) recommends that if amniocentesis is performed, the safest window to reduce risk is between 16-18 weeks. Here is an abstract for more information about amnio.

You may experience some mild cramping or back pain after the procedure. If you experience any leaking, bleeding or fever, you should call your care provider as soon as possible.

Other Facts About Amnio:

  1. Some women with a previous child or a family history of chromosomal abnormalities might also be advised to get an amnio.
  2. If you decide to have an amnio without a definite medical indication, the cost is between $1500 – 2000.
  3. New information shows that the risks of miscarriage with amnio are about the same as those with CVS.

Be sure to review all of options for prenatal testing as you are making your decision.

Do you feel amnio is too risky? Why or why not? Share your feelings about amnio.