Lecture 2

Question 1

Pathological FHR decels share which common theme?

Answer 1

Disruption of normal pathway of O2 from environment to fetus

Question 2

Principles of Fetal Monitoring

Answer 2

1. Maternal vital signs (Physiologic basis for FHR)
2. Oxygenation of maternal-fetal unit (Adequate oxygenation of mom = fetal tolerance of labor)

Question 3

How many arteries and veins comprise the umbilical cord?

Answer 3

2 fetal arteries, 1 vein

Question 4

Which leads to the heart in the fetus: Artery or Vein?

Answer 4

Vein

Artery means “away”: Arteries carry oxygen from the heart through the body

Question 5

What serves as the fetal lung?

Answer 5

Placenta

Question 6

Foramen Ovale

Answer 6

A hole btwn the atria that allows oxygen-rich blood to flow directly to the left atrium, down to the left ventricle, and out the aorta to the brain

Question 7

Ductus Arteriosus

Answer 7

Allows blood to bypass the lungs by going directly from right atrium to right ventricle

Question 8

Normal fetal hematocrit level

Answer 8

15g/dL

Question 9

Definition of Hypoxemia

Answer 9

Decreased oxygen content in blood

Question 10

Definition of Hypoxia

Answer 10

Decreased level of oxygen in tissue (r/t asphyxia)

Question 11

Definition of Acidemia

Answer 11

Increased hydrogen ions in blood

Question 12

Definition of Acidosis

Answer 12

Increased hydrogen ions in tissue (r/t asphyxia)

Question 13

Definition of Asphyxia

Answer 13

Hypoxia with metabolic acidosis

Question 14

2 Point of Contact for External Fetal Monitoring

Answer 14

1. Tocotransducer
   -> To monitor uterine contractions
   -> Placed on fundus
2. Ultrasound transducer (FHR)
   -> Placed lower down, by pelvic bone

Question 15

Definition of Electronic Fetal Monitoring

Answer 15

Electronic method of providing a continuous visual record of the FHR and uterine activity

Information is recorded on graph paper or in archiving database system

Information is permanent part of the maternal medical record

Information is retrievable for litigation

Question 16

How may bpm are counted between each vertical line on tracing paper?

Answer 16

10 bpm

Question 17

How many seconds are counted btwn the vertical bold lines on tracing paper?

Answer 17

60 seconds

Question 18

Definition of a normal HR in fetus

Answer 18

110-160 bpm

Question 19

Definition of Tachycardia in fetus

Answer 19

Above 160 bpm for 10+ minutes

Question 20

Definition of Bradycardia in fetus

Answer 20

Below 110 bpm for 10+ minutes

Question 21

Baseline FHR

Answer 21

Rate in the absence of contractions or periodic changes

Approximate average FHR rounded to increments of 5 bpm during a 10 minute segment

Need 2 minute minimum within those 10 minutes

Question 22

Causes of Tachycardia in FHR: Fetal Conditions

Answer 22

• Hypoxemia
• Anemia
• Sepsis
• Prematurity
• Cardiac dysrhythmias
• Congenital anomalies

Question 23

Causes of Tachycardia in FHR: Maternal Conditions

Answer 23

• Fever
• Dehydration
• Sepsis
• Anxiety
• Thyroid disease
• Drug use

Question 24

Causes of Bradycardia in FHR

Answer 24

• Maternal position (baby is laying on cord)
• Maternal hypotension
• Response to drug administration
• Prolonged maternal hypoglycemia

Question 25

Definition of Variability

Answer 25

- The normal changes and fluctuations in the FHR over a period of time - Significant indicator of fetal well being - Sensitive to hypoxia and acidosis - SHOULD BE WHAT YOU ASSESS FIRST

Question 26

Levels of Variability

Answer 26

Marked: > 25 bpm range Moderate: 6-25 bpm range Minimal: ≤ 5 bpm range Absent: undetectable range

Question 27

Reasons for Minimal Variability

Answer 27

- Hypoxia/acidosis - Drug effects - Fetal sleeping - Congenital anomalies - Extreme prematurity - Fetal tachycardia - Other cardiac dysrhythmias

Question 28

Reasons for Marked Variability

Answer 28

- Increased fetal movement - Hypoxia - Vaginal exam/Fetal stimulation - Second stage/Pushing

Question 29

What is an Acceleration?

Answer 29

Abrupt rises in FHR Most common type of FHR changes These are REASSURING!!

Question 30

What is considered an acceleration?

Answer 30

At ≥ 32 weeks: 15 or more bpm above baseline for 15 seconds or more, but less than 2 minutes Before 32 weeks: shorter height and duration 10 x 10

Question 31

What is the chemical trigger for early decels? NCLEX

Answer 31

Baroreceptors and chemoreceptors

Question 32

Early decels

Answer 32

Onset to nadir ≥ 30 seconds Start to lowest point takes ≥ 30 seconds Decrease and return to baseline FHR associated with uterine contractions Generally seen with first stage of labor Nadir of decels occur at same time as peak of uterine contraction Duration is < 2 minutes

Question 33

Mechanism of Early Decels

Answer 33

- Pressure on the fetal fontanel - Increased intracranial pressure - Dilation is often ~ 4 cm

Question 34

What is the chemical trigger for Variable Decels? NCLEX

Answer 34

Baroreceptors

Question 35

Variable Decels

Answer 35

- Abrupt decrease (onset to nadir < 30 seconds) - Return to baseline FHR may or may not be associated with uterine contractions - "Variable" onset Qualifiers: - Decrease of the FHR ≥ 15 bpm from baseline - Duration ≥ 15 seconds - Duration less than 2 minutes - High BP within circulation drops HR