Fetal surveillance Flashcards
A 42 yo gravida 3, para 1102 at 38 weeks estimated gestational age (EGA) is in labor. She asks about whether she requires electronic fetal monitoring.
fetal surveillance: hx and intention
-In 1958, when the technology was first introduced by Dr Edward Hon, it became possible to evaluate the fetal heart rate electronically in labor
-The fetal heart rate patterns could screen for hypoxic-ischemic encephalopathy, cerebral palsy, and potential fetal demise
-With improvement in anesthesia, blood transfusions, surgical technique, and with better antibiotics, in the postwar era, obstetricians gradually began performing operative deliveries for the welfare of the fetus as well as for that of the patient
-Over time, a perfect or near-perfect outcome for parturient and fetus became the expectation
-Caesarean section also demonstrated that everything possible had been done to deliver a healthy fetus to a healthy patient
-Thus, electronic fetal monitoring became a potential source of litigation as well as a source of data in labor and delivery as well as in prenatal care, when indicated
-A meta-analysis of >37,000 patients found that continuous electronic fetal monitoring is not associated with:
-Improved Apgar scores
-Reduced hypoxic-ischemic encephalopathy
-Neonatal mortality
Electronic fetal monitoring has definitely accomplished one thing:
it has increased the Caesarean section rate
Percent increase in rate of placenta accreta syndrome in the U.S., 1970s-2016
incidence of electronic fetal monitoring
Fetal monitoring is the most common procedure performed in Labor and Delivery units in the United States and is used in over 80% of parturients
when should fetal HR monitoring be performed
-during labor -> intermittently in low risk parturients
-in outpatient settings:
-High risk pregnancies, such as in:
-Diabetes mellitus
-Hypertensive disorders of pregnancy
-And many other conditions
-As indicated, such as in:
-Decreased fetal movement
-Post-term pregnancies
recommendations for performance of intrapartum intermittent auscultation
dont need to know
intermittent auscultation by doppler stethoscope
fetal heart rate monitoring
-Transducer transmits fetal heart tones to monitor equipment
-Tocodynamometer detects uterine contractions
-pt may mark fetal activity
-FHR is read on top part of strip
-Uterine activity is read on bottom part of strip
-110-160 normal HR
-contracting every 1-2 minutes
baseline fetal HR on fetal heart rate strip
-Mean FHR rounded to increments of 5 beats per minute over a 10 minute segment
-Should range from 110-160 bpm
-Baseline FHR <110 bpm: fetal bradycardia
-Baseline FHR >160 bpm: fetal tachycardia
fetal heart rate monitoring: variability
-Amplitude range (from peak HR to trough HR)
-This tracing illustrates variability of 10 BPM (moderate)
-Absent: 0 bpm; an ominous finding
-Minimal: 0-5 bpm; may represent fetal sleep or acidemia
-!!!!Moderate: 5-25 bpm; associated with adequate fetal oxygenation
-Marked: >25 bpm; may be normal variant or may be a response to hypoxemia after oxygenation is restored
-you want moderate variability
-if its minimal- may be asleep
fetal heart rate monitoring: accelerations
-increase in fetal HR from baseline of at least 15 beats per minute, lasting at least 15s
-indicated oxygenated fetus
-Represents fetal well-being
-Increase of ≥15 bpm above baseline lasting ≥15 sec
-accelerations at 2 minutes and another 1 minute later
fetal heart rate monitor: decelerations
-3 types:
-Early (due to head compression; normal in labor) -> could mean pt is dilated and ready to deliver
-Variable (due to cord compression: against uterine wall, against fetal body, compressed by fetal hand)- occasional is fine
-Late (due to uteroplacental insufficiency)- BAD- not enough O2 to placenta
-cause of decelerations:
-compression of uterine myometrial vessels- late
-compression of umbilical cord- variable
-normal compression of fetal head- early
fetal heart monitoring: early decelerations
-Characterized by a GRADUAL (onset to nadir ≥30 sec) decrease in FHR during a uterine contraction
-Nadir of deceleration occurs at the same time as the peak of the contraction
-Caused by !head compression!
-HR 150 baseline
-NORMAL
fetal heart monitoring: variable decelerations
-Defined as an ABRUPT! (ONSET to nadir ≤30 sec) decrease in FHR below the baseline of at least 15 bpm and lasting for at least 15 bpm to up to 2 minutes
-Common in labor
-not always associated with contraction
-!!!Caused by umbilical cord compression
fetal heart monitoring: late decelerations
-Characterized by a GRADUAL (onset to nadir ≥30 sec) decrease in FHR during a uterine contraction
-Onset, nadir and recovery of deceleration occurs after the beginning, peak and end of the contraction -> dont line up
-!!Caused by uteroplacental insufficiency
-late decelerations with absent variability
early, late, and variable decelerations
fetal bradycardia
-<110
-MC during epidural
fetal bradycardia Etiologies
-Parturient:
-Epidural administration
-Uterine dehiscence/rupture
-Cord prolapse
-Rx (narcotics)
-Fetal:
-Fetal hypoxia/acidosis
-Complete heart block in fetus due to maternal SLE
fetal tachycardia etiology
-Maternal etiologies
-Maternal fever
-Maternal infection
-Maternal tachycardia
-Maternal drug use (cocaine, etc.)
-Maternal anxiety
-Fetal etiologies
-Fetal anemia
-Fetal hypoxia
-Fetal infection
-Prematurity
National Institute of Child Health and Human Development (NICHHD) interpretations of electronic fetal monitoring
-In place since 2008
-Developed in partnership with the American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine
-Get the free app: EFM Guide
interpretation of FHRs as per NICHHD, ACOG, and society for maternal fetal medicine guidelines: CATEGORY 1
-Category 1: normal
-MUST CONTAIN ALL OF THE FOLLOWING:
-Baseline FHR=110-160 bpm
-Moderate variability
-Accelerations are present or absent
-Early decelerations are present or absent
-MAY NOT CONTAIN: late or variable decelerations
-category 1 tracings are strongly predictive of normal fetal acid-base balance
-proceed with routine care
reactive strip
-In outpatients, a Category 1 strip with at least two (2) accelerations present in 20-30 minutes is considered to be reactive
-This is usually considered sufficient evidence of good fetal oxygenation so that the patient can be discharged, assuming there are no other concerns
Interpretation of FHRs as per NICHD, ACOG, and Society for Maternal-Fetal Medicine guidelines: CATEGORY 3
-CATEGORY III: ABNORMAL
-OCCURS WITH !ABSENT FHR VARIABILITY!
-!!AND WHEN AT LEAST ONE OF THE FOLLOWING IS ALSO PRESENT:
-Recurrent late decelerations
-Recurrent variable decelerations
-Fetal bradycardia
-Sinusoidal heart rate
-TX:
-May administer O2, or not
-Change maternal position to side
-Consider discontinuation of oxytocin administration
-Increase maternal BP, if indicated, via IV hydration
-!!!Clear any potential obstacles to delivery
-Ensure you have all personnel needed for emergent C/S
-Attending obstetrician-gynecologist
-PA or resident
-Anesthesiologist and/or CRNA
-Scrub nurse or scrub technician
-Circulating nurse
-Neonatologist or pediatrician (one per neonate)
-Neonatal nurse (one per neonate)
-other things you must have:
-Signed, witnessed consent on chart
-Foley catheter
-Adequate anesthesia
-IV antibiotics given
-Antacid given
-prep and drape: splash and clash if needed
Interpretation of FHRs as per NICHD, ACOG, and Society for Maternal-Fetal Medicine guidelines: CATEGORY 2
-CATEGORY II: INDETERMINATE
-Any tracing whose pattern is NOT included in Category I or in Category III
-TX:
-If repetitive or persistent:
-Discontinue uterotonics
-Consider administration O2 to patient via face mask
-However, it is potentially of no benefit
-You may see O2 used, or not used
-Increase IV hydration (1 liter of D5LR IV wide open)
-Turn patient to side to decrease IVC compression and to increase venous return
which of the following categories best describes the tracing displayed
category 1
-moderate variability
-many accelerations
biophysical profile
-assess fetal well being in real time US
-takes up to 30 minutes to perform -> score 0-10
-score 0 OR 2 for each of 5 parameters
-cannot receive score of 1 for a parameter
-8-10/10 is reassuring of no immediate danger of fetal death
-Expeditious delivery is indicated for any score <8/10
Biophysical profile: Parameter 1: Fetal heart rate monitoring
-discussion of fetal monitoring as above
-considered reactive if a category 1 strip with accelerations over the course of 20-30’
-reactive FHR: score 2
-nonreactive FHR: score 0
biophysical profile parameter 2: gross fetal movement
-2 gross movements of body/limb in 30’ (score 2)
-<2 movements: score 0
biophysical profile parameter 3: fetal breathing movements
-Fetal breathing movements: watch chest for rise and fall; must have 1 or more episodes of breathing x 20 sec in 30’
-If absent=score 0
biophysical profile parameter 4: fetal tone
-At least 1 episode of opening and closing hand or extension and flexion of limb and/or trunk during BPP (score 2)
-absent = 0
biophysical profile: parameter 5: amniotic fluid index
-Amniotic fluid index: divide abdomen in 4 quadrants and measure largest vertical pocket of fluid with no fetal parts, cord or placenta in it
-Sum of size of all pockets=AFI
-5-25 cm: normal (score 2)
-<5 cm: oligohydramnios; score 0
->25 cm: polyhydramnios; score 0
which of the following most correctly describes a fetal heart rate pattern consistent with category 2
-baseline of 144 bpm; presence of moderate variability and accelerations
-baseline of 165 bpm; presence of minimal variability and variable decelerations
-baseline of 130 bpm; presence of moderate variability; absence of accelerations or decelerations
-baseline of 150 bpm; absent variability; presence of late decelerations
-variable decerlations
-cat 2
-variable HR
-persistent -> can lead to acidosis if nothing is done
early decelerations
-130bpm
minimal variability
late decelerations
variable intermittent decelerations
-moderate variability
recurrent variable decelerations
-moderate variability
Biophysical profile
