1. Electronic Fetal Monitoring: An Update
James Paul Ching Maganito, DO, MPH, MHA, CHES
Obstetrics and Gynecology
Yakima Valley Farm Workers Clinic
Yakima Valley Memorial Hospital

2. Objective
Refamiliarize ourselves with the recent ACOG practice bulletin guidelines, July 2009
Reemphasize definition to apply to clinical practice and documentation

3. Background FHR monitoring Original research started in the 1960’s
Original rationale – screening test for asphyxia to prevent neurologic damage / fetal death
Original research started in the 1960’s
Study done on term pregnancy noted fetal asphyxia of unknown origin in 63% of the research sample (1)
(1) Low JA, et al. The prediction and preention of intrapartum fetal asphyxia in term pregnancies. Am J Obstet Gynecol 2001; 184:

4. Guidelines for Nomenclature and Interpretation of Electronic Fetal Heart Rate Monitoring
2008
Eunice Kennedy Shriver National Institute of Child Health and Human Development
American College of Obstetricians and Gynecologist
Workshop focused on FHR monitoring
Three goals
To review and update the definitions for FHR pattern categorization from the prior workshop
To assess existing classification systems for interpreting specific FHR patterns and make recommendations about a system for use in the United States
To make recommendations for research priorities for EFM

5. True or False
With regards to uterine contraction, the term hyperstimulation and hypercontractility is still used today and should be adopted and documented?

6. Uterine Contractions Definition
Uterine contractions are quantified as the number of contractions present in a 10 minute window, average over a 30 minute period
Documentation should include: frequency, duration, intensity, relaxation time
Terminologies
Normal: < 5 Ctx in 10min avg over 30min window
Tachysystole: > 5 Ctx in 10min avg over 30min window
Always qualified as to the presence or absence of associated FHR decelerations
Applies to both spontaneous and stimulated labor

7. True or False?
FHR baseline should be document as a range in order to avoid any confusion and give the team a better idea of the characteristic of the baseline?

8. Baseline
FHR rounded to increments of 5bpm during a 10min segment, for at least 2mins, excluding
Periodic or episodic changes
Periods of marked FHR variability
Segments of baseline that differ by more than 25bpm
Normal: bpm
Tachycardia: > 160 bpm
Bradycardia: < 110bpm

9. True or False
Variability should be described and documented as “no,” “good,” or “severe” as well as in terms of short-term versus long-term variability?

10. Baseline Variability Absent: undetectable Minimal: < 5bpm
Moderate: 6-25bpm
Marked: > 25 bpm

11. Accelerations Abrupt increase (onset to peak is < 30secs)
> 32 wk GA, > 15bpm above BL > 15secs but less than 2 mins from onset to return
< 32 wks, > 10bpm above BL > 10secs but less than 2mins from onset to return
Prolonged accelerations last 2mins or more but less than 10mins
> 10 mins is a baseline change

12. True or False
Decelerations are described and documented as persistent, repetitive, or rare?
Decelerations should be described as:
Periodic: associated w/ uterine contractions
Episodic: no association w/ uterine contractions
Recurrent: repetitive

13. Decelerations Early Variable Late Prolonged Sinusoidal
Gradual decrease, nadir = peak of ctx
Variable
Abrupt decrease, > 15 bpm lasting 15 secs but less than 2 mins
Late
Gradual decrease, nadir = after peak of ctx
Prolonged
> 15bpm, lasting > 2 mins but less than 10 mins
Sinusoidal
Smooth, sine wave, cycle frequency of 3-5 per min persisting 20mins or more

14. Classification of FHR Tracing
Category I
Category II
Catergory III

15. Classification of FHR Tracings
Category I
BL: bpm
BL FHR variability: moderate
Accelerations: present
Early Decels: present or absent
Late or variable decels: absent
Monitor Routinely
No Specific Actions required

16. Classsification of FHR Tracing
Category II
BL:
Bradycardia not accompanied by absent variability
Tachycardia
BL Variability
Minimal or marked variability
Absent with no recurrent decels
Accelerations
Absence of induced acceleration after fetal stimulation
Periodic / Episodic decels
Recurrent variable decels
Prolonged decels
Recurrent later decels
Perform Ancillary Test to ensure fetal well being or intrauterine resuscitative measures may be used

17. Classification of FHR Tracing
Category III
BL: Absent with recurrent late/variable decels or bradycardia
Sinusoidal pattern
Prompt evaluation
Depending on clinical scenario, expeditiously resolve abnormal FHR pattern by intrauterine resuscitative efforts
IF NOT resolved – delivery should be undertaken

18. Guidelines for Review of Electronic FHR Monitoring
Pt w/o complications
First stage: q 30mins
Second stage: q 15mins
Pt w/ complications
First stage: q 15mins
Second stage: q 5mins

19. Efficacy of FHR monitoring
INCREASED overall cesarean section delivery rate
INCREASED operative vaginal delivery – vacuum and forcep
Did NOT reduce cerebral palsy risk
False positive rate is > 99% in predicting cerebral palsy
Rationale: 70% of CP occurs before onset of labor & only 4% can be attributed to intrapartum events
Reduced risk of neonatal seizures

20. Poor interobserver and intraobserver variability
The ACOG guidelines highlight a case in which four obstetricians examined 50 FHR tracings; they agreed in only 22% of the cases. Two months later, these four physicians reevaluated the same 50 FHR tracings, and they changed their interpretations on nearly one out of every five tracings.
Foreknowledge of neonatal outcome – alters the reviewer’s impressions of FHR tracings – thus not reliable.

21. Medication Effects on FHR
Narcotics
75mg meperidine (Demerol) = 10mg morphine = 0.1 fentanyl = 10mg nalbuphine (nubain)
Decrease variability, decrease frequency of accels
Butorphanol (Stadol)
Transient sinusoidal pattern
Corticosteroid
Betamethasone: decrease variability – returns to normal by fourth to 7th day post treatment
Dexamethasone: no change
MgSO4
Decreased variability with early gestational age
Mg level did not affect variability
Terbutaline
Increase baseline FHR and incidence of fetal tachycardia

22. Ancillary Test to Aid Management of Category II and III
Fetal Scalp Sampling
Consider with Category III – difficult b/c of decrease in physician experience, difficulty, processing sample
Allis Clamp Scalp Stimulation
Vibroacoustic Stimulation
Digital Scalp Stimulation

23. Intrauterine Resuscitation
Discontinuation of labor stimulating agent
Cervical exam
Determine umbilical cord prolapse
Rapid cervical dilation
Descent of the fetal head
Change maternal position
Monitoring maternal blood pressure level (Hypotension)
If secondary to regional anesthetic, volume expansion or IV ephedrine or both
Assessment of pt for uterine tachysystole
Supplemental oxygen for indeterminate or abnormal patterns
There is no data on the efficacy or safety of this therapy
Tocolytic agent
If position and oxygenation does not change FHR pattern
Although tocolytic therapy appears to reduce the number of FHR abnormalities, there is insufficient evidence to recommend it.
Amnioinfusion
Recurrent variable decels
Decrease rate of decel, decrease hospitalization time of pt and newborn

24. Conclusion Baseline – multiple of 5
Variability – Absent, Minimal, Moderate, Marked
Accels – no asphyxia
Decels: Early, Variable, Late – Periodic, Episodic, Recurrent (Recurrent periodic/episodic)
If in category II and III – physician should be present to evaluate the pt and fetus

25. Lastly…
Computer vs “expert” human visualization, evaluation, and interpretation of electronic fetal heart tracing has been shown to have no statistical difference.

27. Reference
GE: Electronic Fetal Heart Monitoring: Research Guidelines for Interpretation
ACOG Practice Bulletin. Intrapartum Fetal Heart Rate Monitoring: Nomenclature, Interpretation, and General Management Principles. Number 106, July 2009
National Institute of Child Health and Human Development workshop report on electronic fetal monitoring: update on definitions, interpretation, and research guidelines. Obstet Gynecol 2008; 112:661-6