MENNONITE COLLEGE OF NURSING

at

IllinoisStateUniversity

Maternal Infant Nursing -316

Fetal Assessment Worksheet

The purpose of this worksheet is to guide your understanding of the normal fetal heart rate patterns, variations in heart rate patterns during labor, components of the biophysical profile, tests of fetal maturity, and antenatal testing interpretation.

Complete the worksheet and bring it to class on the assigned day. We will review and discuss the content in the worksheet in class. You will be responsible for this material and will be tested on it.

Chapter 21 on Assessment of Fetal Well-being and section on Evaluating Labor Progress & Electronic Fetal Monitoring in Chapter 23 in Olds(9th ed.) to complete most of the questions in this worksheet.

The next two pages of this worksheet and thelast several slides on the Fetal Assessment Powerpoint have current information on fetal monitoring interpretation that would be extremely helpful to you when you are assigned to be in Labor for a clinical day. It would behoove you to bring itwith you to clinical on those days. 

FETAL HEART RATE/VARIABILITY/DECELERATIONS

I.Fetal Heart Rate (FHR)

A.Baseline FHR consists of:

1. The mean of the FHR observed between contractions during a continuous 10- minute period of monitoring rounded to the nearest 5bpm. It does not include the rate during

accelerations or decelerations.

Fetal Heart Rate levels:

Marked bradycardia 70 BPM

Mod. bradycardia 71-99 BPM

Mild bradycardia100-109 BPM

Normal110-160 BPM

Moderate tachycardia161-179 BPM

Marked tachycardia>180 BPM

2.FHR variability-- Baseline variability is a measure of the interplay effect between the sympathetic nervous system and the parasympathetic

• nervous system. It is defined as:

•Fluctuations in the FHR of two cycles permin or greater

•Variability is visually quantitated as the amplitude of peak-to-trough in bpm-
-Absent—amplitude range undetectable-
-Minimal—amplitude range detectable but 5 bpm or fewer-
-Moderate (normal)—amplitude range 6-25 bpm-

-Marked—amplitude range greater than 25 bpm

**Beat-to-beat Variability is probably the most accurate indicator of fetal

well-being that the nurse has. If BTBV is poor, the fetus is probably in distress and needs to be delivered SOON.

B.Periodic changes - changes in FHR, either accelerations or decelerations, from baseline returning to baseline that occur in response to contractions or fetal

movement

1. Accelerations

1. Description--A visually apparent abrupt increase (onset to peak less

than 30 sec.) in the FHR from the most recently calculated baseline

•The duration of an acceleration is defined as the time from the initial change in FHR from baseline to the return of the FHR to baseline

•At 32 weeks of gestation and beyond, an acceleration has an acme of 15 bpm or more above baseline, with a duration of 15 sec. or more but less than 2 min.

•Before 32 weeks gestation an acceleration has an acme of 10 bpm or more above baseline, with a duration of 10 sec. or more but less than 2 min.

•If an acceleration lasts 10 min. or longer it is a baseline change

2. Cause- stimulation of autonomic nervous system of the fetus seen with fetal movement, vaginal exams, abdominal palpation, uterine

contractions. These are usually seen as signs of fetal well-being.

3. Nursing intervention - None.

2.Decelerations-- Periodic decreases in FHR from the normal baseline. There are 3 types that we discuss.

A. Early Decelerations

1. Description--"mirrors" contraction.

In association with a uterine contraction, a visually apparent, gradual (onset to nadir 30 sec. or more) decrease in FHR with return to baseline. *Nadir of the deceleration occurs at the same time as the peak of the contraction

2. Cause - head compression after:

- Uterine contraction

- Vaginal exam

- Fundal pressure

- Placing internal fetal scalp electrode

3. Nursing interventions--benign pattern, no intervention required.

B. Late Decelerations

1.Description

- In association with a uterine contraction, a visually

apparent, gradual (onset to nadir 30 sec. or more) decrease in FHR with return to baseline. Onset, nadir, and recovery of the deceleration occur after the beginning, peak, and end of the contraction, respectively
- Very ominous when associated with loss of STV, rising baseline, or tachycardia

- Repetitious

2.Cause - uteroplacental insufficiency or decreased maternal-fetal

exchange during contractions causing hypoxemia

Seen with

- Hyperstimulation of uterus with oxytocin

- Toxemia

- Postmaturity

- SGA

- Maternal diabetes, anemia, or cardiac disease

- Placenta previa or abruption

3.Nursing interventions

- Change maternal position to left lateral

- Stop Pitocin/Oxytocin if being used

- O2/mask at 7-10L/min

- Correct maternal hypotension

- Increase mainline IV rate (Bolus)

- Elevate legs

C. Variable Decelerations

1. Description-- V, U, or W shaped

An abrupt (onset to nadir less than 30 sec), visually apparent decrease in the FHR below the baseline. The decrease in FHR is 15 bpm or more, with a duration of 15 seconds or more, but < 2 minutes.

2. Cause - umbilical cord compression. If repetitive, it may

indicate nuchal cord (cord around baby’s neck).

3.Nursing Intervention

-Change maternal position

-If severe, may need to try Amnioinfusion

ASSESSMENT OF FETAL WELL-BEING

Chapters 21

MATERNAL ASSESSMENT OF FETAL MOVEMENT

  1. Describe the “Cardiff Count-to-10 Method” or “Daily Fetal Movement Record” (DFMR) method for assessing fetal movement. (sample instructions and chart in Self-Care Guide in back of text). Also see pp383-385.
    Use of Ultrasonography in Pregnancy
  2. Identify and define the 3 levels of ultrasound presently defined by AmericanCollege of Obstetricians and Gynecologists (ACOG).



  6. Name two methods that can be used when performing an ultrasound. Differentiate them. Which can be used earliest in pregnancy?


  9. What information can be obtained from an ultrasound during the first trimester? second?

Third?

  1. Describe the measurements that can be obtained to determine gestational age of the fetus during the pregnancy.

  3. How is ultrasound used to assess placental maturity (grading 0 – 3)? Placental location? Cervical length?
  4. Define IUGR and discuss the importance of early detection in relation to fetal well-being.

ANTENATAL FETAL SURVEILLANCE

  1. Why is Amniotic Fluid Volume (AFV) or Amniotic Fluid Index (AFI) evaluation important in assessing fetal well-being?
  2. Review Tables21-5 & 6 Biophysical Profile (BPP) (p.515) and become familiar with the 5 parameters assessed.
    Think about what two pieces of equipment are used to complete a BPP.
    What are the 2 most important components of the BPP?

Nuchal Translucency Pg. 503.

  1. Define Nuchal Translucency?
  1. What does it detect?
  1. At what gestation is it done?
    OTHER ANTENATAL TESTING

1. Complete the table on the next page on CST, and NST.

2.How is the vibroacoustic stimulator used in an NST?

ANTEPARTAL FETAL HEART RATE MONITORING

Compare/contrast the NonStress Test (NST) & the Contraction Stress Test(CST) by completing the following table.

Nonstress Test (NST)
also called Fetal Activity Determination Test / Contraction Stress Test (CST)
Advantagest
Disadvantages
Procedure
Interpretation of Tests:
What terms are used?
Include criteria used:
Normal / Reactive / Clinical Significance / Negative / Clinical Significance
Abnormal / Nonreactive / Clinical Significance / Positive / Clinical Significance
Equivocal / Unsatisfactory / Clinical Significance / Suspicious
Hyperstimulation
Unsatisfactory / Clinical Significance
Risks to mother & fetus

AMNIOTIC FLUID STUDIES

  1. Contrast how amniocentesis is used early in pregnancy versus later in pregnancy.
  2. What is the significance of the following amniotic fluid studies?
  1. AFP Screening--
    Maternal Serum Alpha Fetal Protein (MSAFP) is a screening tool for which defects in pregnancy? When is the test most accurate? What follow-up testing should be done if an abnormal result is obtained?
  2. Quadruple Check—what are the 4 tests included here? What do they detect?
  3. Bilirubin  OD450/nm - normal value = (ch. 20 pp. 478-479)
  4. L/S Ratio
  5. Phosphatidylglycerol (PG)
  6. Color

OTHER DIAGNOSTIC TESTS

  1. What is Chorionic Villi Sampling and when is Chorionic Villi Sampling (CVS) done during a pregnancy? Why might this be advantageous to the mother?
  2. Fetoscopy is not done as often as in the past because of advances in Sonography and use of PUBS. When might Fetoscopy still be indicated, and what is the nurse’s role during and after the procedure?
  3. What is Cordocentesis/Percutaneous Umbilical Blood Sampling (PUBS) and how is it used during the 2nd and 3rd trimesters to detect fetal status?
  4. What is the significance of fetal fibronectin in relation to preterm delivery?

INTRAPARTUM FETAL MONITORING AND CARE

CHAPTER 23, BASIS FOR MONITORING

  1. What are the goals of Fetal Heart Monitoring (FHM)?
  2. Describe the advantages and disadvantages of external uterine monitoring.

EVALUATION OF UTERINE ACTIVITY

  1. In addition to uterine activity, what other activities of the mother may be reflected on the tracing with the tocodynamometer?
  2. Internal monitoring measures what aspect of the uterine contraction that the external monitor does not measure?
  3. Differentiate between the water-filled intrauterine pressure catheter (IUPC) from the INTRAN IUPC.
    Normal baseline uterine resting tone from an IUPC should remain between _5-15_ mm Hg.
    Normal pressures during uterine contractions should be 50-85 mm Hg.
  4. Hypertonicity of the uterus puts a fetus at risk. How can the nurse detect the effects of hypertonicity on the fetus? What is the nursing action in this situation? (A Critical Thinking Exercise!)
    FYI:

*If uterine pressure is > 30 mm Hg, there is  oxygen getting to baby, but baby usually can compensate.

*If uterine pressure is > 70 mm Hg, there is no perfusion of oxygen getting to the baby. The nurse needs
to monitor closely to see that the fetus is able to cope with the  oxygen supply.

  1. Define the following:
  2. Duration of contraction
  3. Frequency of contraction

(Review deceleration patterns discussed at beginning of worksheet.)

  1. What changes in FHR pattern might you see indicating that the fetus is not coping?
  1. Complete the following table on frequency of fetal monitoring.

Low-RiskHigh-Risk

Frequency of AuscultationPregnancyPregnancy

1st Stage

Latent Phase

Active Phase

2nd Stage

EVALUATION OF FETAL HEART RATE

Match the following terms and/or fetal heart rates:

1.____Normal Fetal Heart Ratea.Periodic changes

2.____Tachycardiab.< 100 BPM

3.____Bradycardiac.110-160 BPM

4.____Moderate tachycardiad.Late Deceleration

5.____Mild Bradycardiae.> 160 for >10 min.

6.____Marked Tachycardiaf.Acceleration

7. ____Moderate bradycardiag.100-109 BPM

8.____Reflects balance between h.160-179 BPM

sympathetic and para- i.Early Deceleration

sympathetic effect on j.> 180 BPM

fetal heart ratek.< 110 for > 10 min.

9.____FHR changes in association l.Variability

with uterine contractionsm.Variable Decels

10.____Caused by fetal head n. < 70 BPM compression

11. __ Marked Bradycardia

12.____Caused by umbilical cord

compression

13.____Caused by uteroplacental

insufficiency

14.____Transient increases in FHR

15.List causes of fetal tachyardia.

16.List causes of fetal bradycardia.

  1. What kinds of drugs may decrease variability?______
  2. Identify what constitutes a reassuring fetal heart rate(FHR) patterns?

a.

b.

c.

d.

  1. Identify what constitutes nonreassuring FHR patterns?

a.

b.

c.

d.

e.

Additional Assessment Techniques

  1. How is fetal scalp stimulation used to to re-establish fetal well-being?
  2. What is the significance of drawing a umblical cord pH?
  3. How does the Base Deficit(BD) reflect either metabolic or respiratory acidosis?

BD and Base Excess(BE) is derived based on the pH, pCO2, H2CO3, and reflects how much base was “used up” during labor.

Cord Blood Gasses

Normal Umbilical Artery levels

pH 7.20

pCO2 < 60

pO2 > 20

BE < -10 or BD < 10

Severity of pH

mild = 7.1 - 7.2

mod = 7.0 - 7.1

severe= < 7.0 usually indicates severe neurological damage

Respiratory Acidemia--usually caused by a build-up of CO2 and not severe

pH < 7.2

pCO2 > 60

pO2 variable

BE < -10

Metabolic Acidemia-- usually caused by hypoxemia and more severe

pH < 7.2

pCO2 <60

pO2 <20

BE < -10

Mixed Respiratory and Metabolic Acidemia

pH < 7.2

pCO2 > 60

pO2 < 20

BE worse

Cord blood gasses are good to have in cases of low Apgar Scores or non-reassuring baselines.

1