EFM

Question 1

What is Cardiotocography

Answer 1

• Electric Fetal Monitoring
• Measures fetal heart rate via external doppler or internal scalp electrode
• Also measures uterine activity
• Uses 2 around the mothers abdomen; 1 for fetal heart rate monitoring and 1 for uterine contractions

Question 2

Montevideo units

Answer 2

• Calculation derived from subtracting the baseline uterine pressure from the peak contraction pressure for each contraction in a 10-min. window and adding the pressures generated by each contraction. In the example shown, there were 5 contractions, producing pressure changes of 52, 50, 47, 44 and 49 mm HG, respectively. The sum of these 5 contractions is 242 Montevideo units

Question 3

Why do we use EFM

Answer 3

• To determine if a fetus is well oxygenated

*fetal brain regulates heart rate thru parasympathetic and sympathetic nervous system

*hypoxia changes activity of nervous system which affects heart rate

*results in changes on EFM

Question 4

Important sings to look for in EFM

Answer 4

• Baseline heart rate

*fetus normal HR is ~160bpm

• Variability

*refers to how squiggly the line is on the monitor

• Presence or absence of accelerations and decelerations

*accelerations are good; HR going up then going back down

*decelerations are bad; HR going down then coming back up

• Frequency of contractions

Question 5

FHR ranges

Answer 5

Fetal hear rate ranges

• Normal baseline: 110-160bpm
• Bradycardia: <110bpm for >10min
• Tachycardia: >160bpm for >10min

Question 6

Causes of abnormal fetal baseline HR chart

Answer 6

Question 7

EFM variability ranges

Answer 7

• Fluctuation in beat to beat rate
• Amplitude of peak-to-trough in bpm
• Absent: amplitude range undetectable

*never want; baby needs to be delivered ASAP

• Minimal: amplitude rang <5bpm
• Moderate: amplitude range 6-25bpm
• Marked: amplitude range >25bpm

Question 8

EFM Variability Chart examples

Answer 8

Question 9

Variability significance

Answer 9

• Variability is sensitive to fetal biochemical (acid-base) status
• Moderate variability suggests adequate oxygenation
• Decreased variability is assoc. w/:

*medications (opiods, magnesium sulfate)

*fetal sleep cycle

*prematurity

*CNS or cardiac abnormalities

*fetal hypoxia

*fetal acidemia

Question 10

EFM Sinusoidal pattern

Answer 10

• Smooth sine wave-like undulating pattern in FHR baseline
• Cycle freq. of 3-5per min
• Persists for 20min or more
• Assoc. w/ severe fetal anemia
• Transient pattern can be assoc. w/ maternal administration of butophanol (Stadol)

Question 11

EFM Accelerations

Answer 11

• Abrupt increase in FHR w/ peak of >15 beats above baseline
• Duration of at least 15sec, up to 2min

*if duration is >2min, it is a prolonged acceleration

*if duration is >10min, it is a change in baseline

• Assoc. w/ fetal mvmt
• Demonstrates a mature neurocardiac tract
• Usually indicates the fetus is not acidemic
• Reassuring of fetal well-being

Question 12

EFM Decelerations

Answer 12

• Decrease in FHR from baseline
• Descriptions

*recurrent: decel occurs w/ >50% of contractions

*intermittent: occurs w/ <50% of contractions

• Types:

*early: assoc. w/ head compression (not so bad)

*variable: assoc. w/ cord compression (okay)

*late: assoc. w/ uteroplacental insufficiency (bad)

Question 13

Early Decelerations

Answer 13

• Mirrors contraction—>starts at onset of contraction, nadirs at peak of contraction, returns to baseline at end of contraction
• Onset of nadir >30sec
• Due to head compression that stimulates the vagal nerve
• No treatment necessary, consider checking pt as head is probably descending

Question 14

Variable Decelerations

Answer 14

• Babies HR decelerates to compensate for something going wrong
• Abrupt decrease in FHR wher onset to nadir is <30sec
• Decrease in FHR is >15bpm w/ total duration >15sec
• “V” config
• Due to vagal response from cord compression
• Not necessarily assoc. w/ contraction, can occur at any time
• Can cause fetal hypoxia if persistent

Question 15

Decelerations Interventions

Answer 15

• Maternal repositioning

*decelerations could be compensating for cord compression and by moving mother you can shift things relieving the pressure on cord

• Amnioinfusion

*places intrauterine fluid via IVF/IUPC

• Check patient

*if prolapsed cord is palpated, elevate presenting fetal part while preparations are made for operative delivery

• GOAL IS TO ALLEVIATE CORD COMPRESSION

Question 16

Late Decelerations

Answer 16

• Symmetrical gradual decrease in FHR
• Begins at or after peak of contraction and returns to baseline after contraction is over
• Assoc. w/ uteroplacental insufficiency from decreased uterine perfusion or decreased placental function

*post-term pregnancy, placental abruption, maternal hypertension/hypotension, maternal DM, maternal anemia, maternal sepsis, uterine tachysystole

Question 17

Late Decelerations Interventions

Answer 17

• Maternal repositioning—> left or right lateral
• Maternal oxygen admin
• Administer IV fluid bolus
• Reduce contraction freq.

*discontinue oxytocin or cervical ripening age

*administer tocolytic medication

• GOAT IS TO IMPROVE UTEROPLACENTAL BLOOD FLOW

Question 18

“A-B-C-D” Approach to decelerations

Answer 18

• Assess oxygen pathway
• Begin conservative corrective measures
• Clear obstacles to rapid delivery
• Determine decision-to-delivery time

Question 19

When do we need to expedite delivery?

Answer 19

• At FHR category 3

Question 20

Decelerations Chart

Answer 20

Question 21

Category 1 FHR tracings

Answer 21

Category 1 FHR tracings include all of the following:

• Baseline rate: 110-160bpm
• Baseline FHR variability: moderate
• Late or variable decelerations: absent
• Early decelerations: present or absent
• Accelerations: present or absent
• Assoc. w/ normal acid-base status

Question 22

Category 3 FHR tracings

Answer 22

Category III FHR tracings include either:

• Absent baseline FHR variability and any of the following:

*recurrent late decelerations

*recurrent variable decelerations

*bradycardia

• Sinusoidal pattern
• Assoc. w/ abnormal acid-base status

Question 23

Category 2 FHR tracings

Answer 23

• Everything else not in category 1 or 3
• Assoc. w/ indeterminate acid-base status; i.e. not predictive of either normal or abnormal

Question 24

3 Tier FHR Classification Chart

Answer 24

Question 25

Normal FHR Strip

Answer 25

Question 26

Management of Category 1

Answer 26

- No interventions necessary - This is reassuring that fetus is not acidemic

Question 27

Management of Category 2

Answer 27

- Requires eval, continues monitoring, and possibly intrauterine resuscitation - Interventions include: \*maternal repositioning \*maternal oxygen admin \*IVF \*reduce contraction freq \*possible amnioinfusion (if variable decels) - Presence of moderate variability and accelerations are reassuring that fetus is not acidemic

Question 28

Management of Category 3

Answer 28

- Requires intrauterine resuscitation - If unresolved, deliver pt

Question 29

Uterine Activity

Answer 29

- Contractions are quantified as number of contractions present in 10min window averaged over 30min - Duration, intensity, and relaxation time b/w contractions are also important - Normal: \<5 contractions in 10min averaged over a 30min window - Tachysystole: \>5 contractions in 10min averaged over a 30min window

Question 30

Normal contraction pattern

Answer 30

- \<5 contractions in 10min averaged over a 30min window

Question 31

Tachysystole contractions pattern

Answer 31

- \>5 contractions in 10min averaged over a 30min window