WITH ACCURATE ANSWERS AND
EXPLANATIONS
Describe Fetal Heart Rate Monitoring - ANSWER✔✔✨---EFM may be external, internal or a
combination
In the US, the majority of women have EFM during some or all of their labors
Each modality has both pros and cons
Describe Doppler Ultrasound - ANSWER✔✔✨---The doppler US transducer is used to assess FHR
characteristics and patterns. The transducer translates sound wave reflections into waveforms which are
interpreted by a computer and then exported as an audible sound and a waveform pattern.
Problems: FHR artifact, doubling, halving, and detection of maternal heart rate
Current ultrasound FHR signal processing uses autocorrelation techniques and interpretation of EFM
data is based on this assumption
Describe internal fetal electrode - ANSWER✔✔✨---The FSE directly measures the FHR by measuring
R to R waves in successive QRS complexes. To place an FSE, adequate cervical dilation (usually at least 2
cm) and ROM are needed.
Contraindications: placenta previa, hemophilia, maternal HIV, herpes infections, or when presenting
part is not identifiable
Problems: artifact, slight risk of fetal infection/injury, doubling or halving of the FHR, and pick up of the
MHR with fetal demise
,Other relative contraindications: syphilis, gonorrhea (not recommended but may be placed if a clear
benefit to a mother and fetus can be demonstrated by its use)
Describe external uterine monitoring - ANSWER✔✔✨---The tocotransducer (TOCO) is a pressure
sensitive button-like device that detects changes in the abdominal contour when there is a uterine
contraction. The specific location is determined by abdominal palpation and is ideally a smooth part of
the uterus where no fetal small parts are felt. Usually this is the fundus or whatever uterine contractions
are most easily palpated
The TOCO can best provide: relative strength, approximate duration, and approximate frequency of
contractions but cannot determine actual intensity. PALPATION IS ESSENTIAL
Problems: include its inherent limitations, possibility of inverted contractions and issues with obesity
Describe internal uterine monitoring - ANSWER✔✔✨---IUPC allows for greater quantitative
measurement of uterine contraction frequency, duration, and intensity or peak intrauterine pressure
and resting tone
Three types: fluid-filled (other countries), transducer-tipped, and air-coupled or sensor-tipped (what we
used)
Measures: actual pressures in mmHg and most allow for amnioinfustion
Indications for use: Need for amnioinfusion, titration of oxytocin for induction or augmentation when
external methods are not providing enough information, and lack of progress in labor
Problems: user error, displacement, placental abruption/shearing, and a small risk of uterine perforation
What are the three types of IUPC monitors? - ANSWER✔✔✨---Fluid-filled: also called the water
column method, was the 1st type of IUPC available and use dramatically decreased after introduction of
the transducer-tipped catheter. It works by transmitting the pressure generated by a contraction
through a water column to a transducer located away from the source of pressure, typically at the
, monitor site. This displaced fluid exerts pressure against a diaphragm in the transducer, generating
changes in the electrical resistance of a series of wires. These electrical changes are converted to
measures of pressure.
Transducer-tipped: Introduced in the 1980s as an alternative to fluid-filled. The force exerted by a
uterine contraction is converted to an electrical signal that is transmitted through a wire system to a
fetal monitor where the uterine activity is displayed graphically on the fetal monitor tracing
Sensor-tipped: Air-coupling technology, which is a newer method of IUPC monitoring, uses a distally
mounted flexible balloon in the uterus connected to an external reusable transducer in the monitor
cable. Similar to noninvasive blood pressure monitors, this catheter consists of a membrane sensor at
the tip of the catheter that communiated pressures through a microcolumn of air to a transducer
located outside the body
What is the paper speed for EFM tracing? - ANSWER✔✔✨---Changes in paper speed can
substantially alter the appearance of the tracing. The commonly used paper in the US has markings on
the vertical scale from 30-240 bpm with dividing lines at 10-bpm intervals. Should be set to 3cm on the
horizontal scale (slower than Europe)
What is artifact? - ANSWER✔✔✨---Irregular variations or absence of the FHR on the fetal monitor
record resulting from mechanical limitations of the monitor, electrical interference, or weak signal,
appearing as gaps or dots. With FSE, artifact may appear in the form of irregular lines with varying
lengths.
FSE artifact vs arrhythmias: arrhythmias will be regular lines
What is half-counting in regards to the FHR? - ANSWER✔✔✨---Most commonly seen when the FHR
is rapid, such as with fetal supraventricular tachycardia
What is double-counting in regards to FHR? - ANSWER✔✔✨---May occur during periods of
bradycardia
What are some troubleshooting interventions for fetal monitoring? - ANSWER✔✔✨---Repositioning
the US transducer, ensuring an adequate amount of coupling gel is used, and checking for proper
placement of FSE