Antenatal Testing

Question 1

What is a Non Stress Test (NST)?

Answer 1

Simple fetal heart rate (FHR) monitoring. Looks for accelerations and variability.

Question 2

What is a Reactive NST?

Answer 2

2 accelerations of
15bpm above baseline
lasting 15 seconds
in a 20min period

(non-reactive test lacks one of the 4 items)

Question 3

When is an NST performed?

Answer 3

Usually after 32 weeks

Question 4

What is the Contraction Stress Test (CST) and when is it done?

Answer 4

Oxytocin Stress Test or Nipple Stim test. Best if done after 37 weeks because it may induce labor. This test is done to check the fetus’s response to a stressful situation (including labor).

Question 5

What is a positive CST?

Answer 5

3 contractions
lasting 40-60 seconds
in a 10 min. period

Question 6

Which CST result has the best outcome?

Answer 6

You want a negative CST: no late HR decelerations along with adequate uterine contractions

Question 7

What is the Biophysical Profile (BPP)?

Answer 7

Tests progress of pregnancy when risk factors are present such as diabetes, pre-Eclampsia, post date, IUGR, or previous stillbirth

Question 8

What 5 items are tested in a BPP?

Answer 8

Fetal Breathing movement: at least one episode of more than 30 seconds in a 30min period (2points)

Gross body movement: 3 body or limb in a 30 minute period (2 points)

Fetal Tone: one episode of active extension of limbs hands or trunk (2 points)

NST: reactive is 2 points

Amniotic Fluid Volume: at least one pocket of amniotic fluid volume measuring 2cm in two perpendicular planes (2 points)

Question 9

Which item of the BPP is most important and which is least?

Answer 9

Amniotic fluid volume is most important (if there is oligohydramnios, deliver immediately even with a score of 8)

Breathing is least important