Ronald Reagan UCLA Medical Center
757 Westwood Plaza
Fifth Floor, Suite 5511
Los Angeles, CA 90095

About Our Center


The Fetal Diagnostics Unit provides a range of antepartum diagnostic services, including biophysical profiles and amniocentesis. The most common tests performed are the non-stress fetal-heart-rate test (NST) and measurement of the amniotic fluid index (AFI). Procedures are performed by a nurse who specializes in fetal testing.

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Frequently Asked Questions

Why do I need these tests?
Your physician may order antenatal testing if you or your baby requires special medical care or extra attention during your pregnancy. Your physician might refer you for evaluation of such issues as:

  • Going past due date
  • Diabetes
  • High blood pressure
  • Small baby or baby not growing
  • Less active baby
  • History of prior stillbirth
  • Low amniotic fluid index
  • Multiples

What are the NST and AFI tests?
A NST is a non-invasive procedure to monitor and record your baby's heartbeat for a minimum of 20 minutes. An AFI measures the amount of amniotic fluid surrounding your baby. The purpose of these tests is to assess fetal well-being and fetal oxygenation.

How are these tests done?
The AFI involves a limited ultrasound to look at four areas of your uterus to determine the quantity of amniotic fluid and whether there is enough, too much or too little. The location of the placenta, the baby's heartbeat and position are also evaluated.

For an NST, you lie on your left side and elastic belts are placed around your abdomen to monitor and record the baby's heartbeat, movements and uterine activity such as contractions. You will be asked to eat before the test because some babies move more after mothers have eaten. The NST is "reactive" if the baby's heartbeat increases at least two times in 20 minutes. If your baby is quiet and not moving, we may give you water to drink or change your position to continue monitoring. The NST is "non-reactive" if the baby's heart does not beat faster with movement or if the baby continues to be quiet and not moving. "Non-reactive" does not mean that something is wrong. It simply means the NST has not provided sufficient information. After consultation with your physician, further tests such as a biophysical profile or prolonged monitoring may be ordered.

NSTs and AFIs are usually performed once or twice a week. Your physician will determine when during your pregnancy the tests should be started and the frequency of testing. We will try to schedule your tests on the same day as your doctor's appointment.

Can I monitor my baby's movements when I am away from the hospital?
Yes, you can. It is important to be aware of and keep track of your baby's movements in order to help prevent stillbirth. If you don't feel your baby moving at the times of day he/she usually moves or is active, you should perform a fetal kick/movement count. Ideally, this should be done after you have eaten a snack or small meal. If, after eating, you cannot feel at least 10 movements in less than two hours, call your physician and come to the Fetal Diagnostic Unit or Labor & Delivery for testing.

Useful Information

Appointments are available weekdays from 8 am to 3 pm. We are typically closed on weekends and major holidays.

Most tests can be completed in one hour, although test times can range between 20 minutes and a few hours.

No special preparation is required, although we do prefer that expectant parents eat something before coming in for testing, as babies tend to move more after meals.

Wear something comfortable, preferably a two-piece outfit, to allow easier access to your abdomen.

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