Amniocentesis
How It Is Done
Amniocentesis is done by your obstetrician in his or her office or in the hospital. An overnight stay in the hospital usually is not needed unless problems occur during the test.
You will be asked to expose your belly. You will then lie on your back with it slightly raised to relax your belly muscles. Your lower belly will be cleaned with a special soap.
Your doctor checks the position of your baby and the placenta with a fetal ultrasound. Ultrasound uses sound waves to make a picture of the uterus, your baby, and the placenta on a TV screen. Your baby's heart rate can also be watched during the test using ultrasound. For more information, see the medical test Fetal Ultrasound.
With the ultrasound picture as a guide, your doctor gently puts a long thin needle through your belly and into your uterus without hurting your baby or the placenta. If your baby moves too close to the needle, the needle will be taken out and your doctor will try again in another spot.
About 30 mL (2 Tbsp) of amniotic fluid is taken out in a syringe attached to the needle, and then the needle is taken out. The site is covered with a bandage.
See an illustration of the amniocentesis test
.
The whole test takes about 15 minutes. The thin needle is only in your belly for 1 to 2 minutes. Your baby's heart rate and your blood pressure, pulse, and breathing will be checked before, during, and after the test.
 Go to previous section |  Go to top of page |  Go to next section |
| Author: | Jan Nissl, RN, BS Sydney Youngerman-Cole, RN, BSN, RNC | Last Updated: October 12, 2006 |
| Medical Review: | Renée M. Crichlow, MD - Family Medicine Siobhan M. Dolan, MD, MPH - Reproductive Genetics Liisa Honey, MD, FRCSC - Obstetrics and Gynecology | |
 | ||
| |
| Topic Contents | |
| Test Overview | |
Health Tools  | |
| Why It Is Done | |
| How To Prepare | |
 | How It Is Done |
| How It Feels | |
| Risks | |
| Results | |
| What Affects the Test | |
| What To Think About | |
| References | |
| Credits | |