What is Amniocentesis? Video Transcript

Participants

Joan Atkin MD, Unjera Jackson MD, FACOG, Marty Moss-Coane

Summary

If your doctor has suggested amniocentesis you probably have a lot of questions and concerns. Is the procedure safe for you and your child? What are the chances that an abnormality will be found? What decisions will you be faced with if there is an abnormality? Join our panel of experts for a close look at this important procedure.

Webcast Transcript

MARTY MOSS-COANE: Welcome to our webcast. I'm Marty Moss-Coane. When a couple finds out that they're going to have a baby, it's a cause for celebration. But for some couples, there are questions about the health of their newborn. With all the advances in medicine, doctors and their patients can learn a lot about the development of a fetus, and one of the tools that's commonly used is amniocentesis. This is a procedure which involves removing a small portion of the amniotic fluid which surrounds the fetus. It was first tried many years ago, and today is used in the second trimester to determine if certain birth defects are present.

On our webcast: What you need to know about amniocentesis. We have two guests. Dr. Unjera Jackson is a maternal/fetal medicine specialist and Director of Obstetrics at Morristown Memorial Hospital in Morristown, New Jersey. Dr. Jackson, nice to have you with us. Dr. Joan Atkin is a medical geneticist, and Director of Genetics at Atlantic Health System, also in New Jersey. Dr. Atkin, nice to have you with us as well.

To you, Dr. Atkin, what is in the amniotic fluid that makes it so important for amniocentesis?

JOAN ATKIN, MD: Those are fetal cells, cells that have actually shed from the fetus. They come from the skin, from the GI tract, from the lungs, and from the bladder. We're actually looking at fetal cells when we do testing from the amniotic fluid. So it's not the fluid per se that's important, but the cells in the fluid.

MARTY MOSS-COANE: I'm interested, Dr. Jackson, what indicators, to you as an obstetrician, would be a reason for amniocentesis?

UNJERA JACKSON, MD: The primary indicators for amniocentesis would be the mother being age 35 or older at the time of the delivery, a known family history for which genetic antenatal testing can be used to determine whether the baby is affected. A prior child who has been affected with a chromosomal abnormality or some other inherited condition. And, additionally, an abnormal ultrasound in and of itself could be an indicator for an amniocentesis.

And also, during the second trimester, we routinely offer triple screen tests, which includes looking at maternal serum alpha-fetoprotein, something called the free-beta, and an estriol level, to come up with a calculated risk which uses the patient's age, the number of fetuses she's carrying, and a variety of other parameters to calculate a risk. And if she's at increased risk, based on this particular blood test, then that would be an indication for proceeding with an amniocentesis also.

MARTY MOSS-COANE: How about for multiple births? Is that an indicator for amniocentesis?

UNJERA JACKSON, MD: Multiple births in and of itself would not be. The criteria would be age, prior history, an abnormal fetus being picked up at the time of an ultrasound, or an abnormal triple screen.

MARTY MOSS-COANE: When you say an abnormal triple screen, I just want to make sure that the audience understands what exactly that means. This is this blood test that you had mentioned?

UNJERA JACKSON, MD: This is the blood test that is offered between 15 and 19 weeks, although performing the test earlier is better, because then you have time to do the additional workup. Again, looking at the three parameters that I mentioned, in order to come up with some numbers that determine whether the patient's at increased risk, for example, for Down syndrome, which is trisomy-21, or trisomy-18, or open neural tube defects.

MARTY MOSS-COANE: You want to add to that, Dr. Atkin?

JOAN ATKIN, MD: The triple-screen test, I think, a lot of times patients don't understand at all.