Basic Electronic Fetal Heart Monitoring
What does fetal monitoring tell us? - ANS-- Fetal oxygenation
- Acid-base status of the fetus
- Ability of the CNS to regulate FHR
- Why monitor? Prevention of hypoxia/asphyxia
Consequences of Inutero Hypoxia/Asphyxia - ANS-- Cerebral Palsy
- Mental retardation
- Epilepsy
- RDS (Respiratory Distress Syndrome)
- Renal damage
- NEC (Necrotizing Enterocolitis) = lack of O2 to gut --> permanent damage or necrosis
- Chronic brain impairment (permanent brain damage) = lack of O2 during birthing
process
Internal Fetal Monitoring - ANS-- IUPC (an internal contraction monitor) = introduced
through cervix and floats beside the baby
- FSE (an internal fetal heart monitor) = attached to baby's skin on head
- Used when fetus or mom keeps moving/repositioning
*Conditions: BOW must have ruptured and cervix must be dilated at least 3 cm
Monitoring Fetal Heart Rate - ANS-- External = Ultrasound device
- Internal = Fetal scalp electrode (FSE)
Monitoring Contractions - ANS-- External = Toco transducer
- Internal = Intrauterine pressure catheter (IUPC)
Remember... - ANS-- The intensity of contractions can only be measured objectively
with an IUPC in place
- Without it, the nurse must assess the strength of the contraction subjectively by
palpating the fundus during a contraction
- If the fundus tone feels like:
-- Tip of the nose = mild contraction
-- Chin = moderate contraction
-- Forehead = strong contraction
, Fetal Heart Monitoring - ANS-- Top tracing represents FHR
- Bottom tracing represents contractions
Counting Contractions - ANS-- Duration: From the beginning to the end of one
contraction (length of contraction)
- Frequency: Beginning of one contraction to the beginning of the next contraction
Uterine Perfusion During Contractions - ANS-Change in uterine blood flow with
contractions
Three Important Components of the Fetal Heart Monitor Strip - ANS-Baseline Heart
Rate
- Is it normal, bradycardia, tachycardia?
Variability
- Is it present or absent?
Periodic Changes
- Accelerations (increases in fetal HR)
- Decelerations: (decreases in fetal HR)
1. Early Decels (Benign)
2. Late Decels (Ominous)
3. Variable Decels (Ominous)
Basic Pattern Recognition - ANS-- Baseline FHR: 110-160 for 10 min.
- Tachycardia: FHR >160 for >10 min.
-- Most common cause is maternal infection
- Bradycardia: FHR <110 for > 10 min.
Variability - ANS-- The "squiggliness" of the FHR tracing
- Baseline variability is a measure of the interplay (the push-pull effect) between the
sympathetic and parasympathetic nervous systems
- Lack of variability is ominous
- Variability is the best indicator of fetal well-being
Periodic Changes: Accelerations - ANS-Transient increases above the FHR baseline
- Fetal movement
- Contractions
- Accelerations are positive/reassuring
What does fetal monitoring tell us? - ANS-- Fetal oxygenation
- Acid-base status of the fetus
- Ability of the CNS to regulate FHR
- Why monitor? Prevention of hypoxia/asphyxia
Consequences of Inutero Hypoxia/Asphyxia - ANS-- Cerebral Palsy
- Mental retardation
- Epilepsy
- RDS (Respiratory Distress Syndrome)
- Renal damage
- NEC (Necrotizing Enterocolitis) = lack of O2 to gut --> permanent damage or necrosis
- Chronic brain impairment (permanent brain damage) = lack of O2 during birthing
process
Internal Fetal Monitoring - ANS-- IUPC (an internal contraction monitor) = introduced
through cervix and floats beside the baby
- FSE (an internal fetal heart monitor) = attached to baby's skin on head
- Used when fetus or mom keeps moving/repositioning
*Conditions: BOW must have ruptured and cervix must be dilated at least 3 cm
Monitoring Fetal Heart Rate - ANS-- External = Ultrasound device
- Internal = Fetal scalp electrode (FSE)
Monitoring Contractions - ANS-- External = Toco transducer
- Internal = Intrauterine pressure catheter (IUPC)
Remember... - ANS-- The intensity of contractions can only be measured objectively
with an IUPC in place
- Without it, the nurse must assess the strength of the contraction subjectively by
palpating the fundus during a contraction
- If the fundus tone feels like:
-- Tip of the nose = mild contraction
-- Chin = moderate contraction
-- Forehead = strong contraction
, Fetal Heart Monitoring - ANS-- Top tracing represents FHR
- Bottom tracing represents contractions
Counting Contractions - ANS-- Duration: From the beginning to the end of one
contraction (length of contraction)
- Frequency: Beginning of one contraction to the beginning of the next contraction
Uterine Perfusion During Contractions - ANS-Change in uterine blood flow with
contractions
Three Important Components of the Fetal Heart Monitor Strip - ANS-Baseline Heart
Rate
- Is it normal, bradycardia, tachycardia?
Variability
- Is it present or absent?
Periodic Changes
- Accelerations (increases in fetal HR)
- Decelerations: (decreases in fetal HR)
1. Early Decels (Benign)
2. Late Decels (Ominous)
3. Variable Decels (Ominous)
Basic Pattern Recognition - ANS-- Baseline FHR: 110-160 for 10 min.
- Tachycardia: FHR >160 for >10 min.
-- Most common cause is maternal infection
- Bradycardia: FHR <110 for > 10 min.
Variability - ANS-- The "squiggliness" of the FHR tracing
- Baseline variability is a measure of the interplay (the push-pull effect) between the
sympathetic and parasympathetic nervous systems
- Lack of variability is ominous
- Variability is the best indicator of fetal well-being
Periodic Changes: Accelerations - ANS-Transient increases above the FHR baseline
- Fetal movement
- Contractions
- Accelerations are positive/reassuring
