Antenatal fetal surveillance

Question 1

What is a Non-Stress Test (NST), and when is it indicated?

Answer 1

An NST is a test used to monitor fetal heart rate in response to fetal movements, assessing fetal well-being. It is indicated for pregnancies at risk of intrauterine fetal compromise, such as prolonged pregnancy, maternal hypertensive disorders, IUGR, diabetes, and reported decreased fetal movements.

Question 2

What are the criteria for a reactive Non-Stress Test (NST)?

Answer 2

A reactive NST has at least 2 accelerations of 15 bpm above baseline lasting at least 15 seconds within 20 minutes, with moderate variability and a baseline fetal heart rate between 110-160 bpm

Question 3

What does a Biophysical Profile (BPP) assess, and what is considered a suspicious score?

Answer 3

A BPP assesses fetal breathing, gross body movements, fetal tone, amniotic fluid volume, and includes an NST. A score of 6 or below (out of 10) is suspicious for fetal hypoxemia

Question 4

What is the Modified Biophysical Profile (Modified BPP), and how is it interpreted?

Answer 4

The Modified BPP combines the Amniotic Fluid Index (AFI) with an NST. It is considered normal if the AFI is greater than 5 cm and the NST is reactive.

Question 5

How should fetal heart rate be monitored intrapartum?

Answer 5

Fetal heart rate should be evaluated for at least 1 minute upon admission and during active labor every 30 minutes using a fetoscope or Doppler. Abnormal findings, such as bradycardia, tachycardia, or persistent decelerations, require further evaluation.

Question 6

What are the key indicators of an abnormal Cardiotocogram (CTG)?

Answer 6

Key indicators of an abnormal CTG include late decelerations, sinusoidal patterns (suggesting fetal anemia), and variable decelerations that persist or occur without contractions.

Question 7

What steps should be taken if a CTG shows signs of fetal distress?

Answer 7

If a CTG shows signs of fetal distress, evaluate the cause, place the woman in the left lateral position, stop oxytocin if being used, administer a tocolytic if there is hyperstimulation, provide IV fluids if hypotension is present, give oxygen if available, and consider urgent delivery if necessary.

Question 8

What is a Biophysical Profile (BPP), and what does it assess?

Answer 8

A Biophysical Profile (BPP) is an antenatal test that assesses fetal well-being by evaluating five components: fetal breathing movements, gross body movements, fetal tone, amniotic fluid volume, and a Non-Stress Test (NST).

Question 9

How is fetal breathing assessed in a Biophysical Profile (BPP)?

Answer 9

Fetal breathing is assessed by observing at least one episode of rhythmic breathing lasting at least 30 seconds within a 30-minute period.

Question 10

What criteria are used to assess gross body movements in a Biophysical Profile (BPP)?

Answer 10

Gross body movements are assessed by observing at least three discrete body or limb movements within a 30-minute period.

Question 11

How is fetal tone evaluated in a Biophysical Profile (BPP)?

Answer 11

Fetal tone is evaluated by observing at least one episode of active extension and flexion of a limb or the opening and closing of a hand.

Question 12

What is the significance of amniotic fluid volume in a Biophysical Profile (BPP), and how is it measured?

Answer 12

Amniotic fluid volume is an indicator of fetal well-being. It is measured by identifying at least one pocket of amniotic fluid that is at least 2 cm in two perpendicular planes.

Question 13

How is the Non-Stress Test (NST) component of the BPP scored?

Answer 13

The NST is scored by assessing whether there are at least two accelerations of 15 bpm above baseline lasting at least 15 seconds within a 20-minute period. A reactive NST receives 2 points, while a non-reactive NST receives 0 points.

Question 14

How is the total score of a Biophysical Profile (BPP) interpreted?

Answer 14

The BPP score ranges from 0 to 10, with each of the five components scoring either 2 points (normal) or 0 points (abnormal). A score of 8-10 is generally reassuring, 6 is considered equivocal, and 4 or less is suspicious for fetal hypoxemia, warranting further evaluation or intervention.

Question 15

What actions should be taken if a Biophysical Profile (BPP) score is 6 or lower?

Answer 15

If the BPP score is 6 or lower, it suggests possible fetal hypoxemia. Further evaluation, such as repeating the test or considering delivery, should be considered depending on gestational age and other clinical factors.

Question 16

What are the key components of a CTG trace?

Answer 16

The key components of a CTG trace include the baseline fetal heart rate (FHR), variability, accelerations, decelerations, and the pattern of uterine contractions.

Question 17

What is the normal range for baseline fetal heart rate (FHR) on a CTG?

Answer 17

The normal baseline fetal heart rate (FHR) on a CTG ranges from 110 to 160 beats per minute (bpm).

Question 18

What does variability in a CTG trace indicate, and what is considered normal?

Answer 18

Variability refers to the fluctuations in the fetal heart rate around the baseline. It is a sign of fetal well-being. Normal variability is between 5 to 25 bpm.

Question 19

What are accelerations in a CTG, and what do they signify?

Answer 19

Accelerations are transient increases in the fetal heart rate of at least 15 bpm above the baseline lasting at least 15 seconds. They are generally considered a reassuring sign of fetal well-being.

Question 20

What are the different types of decelerations seen on a CTG, and what do they indicate?

Answer 20

Early Decelerations: Gradual decreases in FHR that mirror contractions, often due to fetal head compression. They are usually benign.
Late Decelerations: Gradual decreases in FHR beginning after the contraction starts, often indicating uteroplacental insufficiency and fetal hypoxia.
Variable Decelerations: Abrupt decreases in FHR that can vary in duration and intensity, usually associated with umbilical cord compression. They may be benign or concerning, depending on the pattern.
Prolonged Decelerations: Decreases in FHR lasting more than 2 minutes but less than 10 minutes, often indicating significant fetal distress.

Question 21

What is a sinusoidal pattern on a CTG, and what does it suggest?

Answer 21

A sinusoidal pattern is a smooth, wave-like, undulating pattern in the FHR baseline with no variability. It suggests severe fetal anemia or hypoxia and is associated with a high risk of fetal compromise.

Question 22

What actions should be taken if a CTG shows signs of fetal distress?

Answer 22

If a CTG shows signs of fetal distress, immediate actions may include:
Repositioning the mother to the left lateral position to improve blood flow to the fetus.
Stopping oxytocin if being used to reduce uterine contractions.
Administering a tocolytic if there is uterine hyperstimulation.
Providing IV fluids or oxygen to the mother.
Preparing for urgent delivery (Cesarean section or operative vaginal delivery) if the distress persists.

Question 23

What are the indications for using a CTG?

Answer 23

Indications for using a CTG include maternal hypertensive disorders, suspected intrauterine growth restriction (IUGR), oligohydramnios, preterm labor, induction or augmentation of labor, previous Cesarean section in active labor, and any other situation where fetal distress is suspected.