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Fetal Monitoring & Wellbeing. Fetal Well-being. Principles: the ideal scheme to assess FWB should: Take account of cycles of normal fetal behavior detect impending harm accurately and in time to intervene to prevent it give reassurance preferably up to 7 days - PowerPoint PPT Presentation
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Principles:
the ideal scheme to assess FWB should:
Take account of cycles of normal fetal behavior
detect impending harm accurately and in time to intervene to prevent it
give reassurance preferably up to 7 days
avoid causing unnecessary anxiety
allow detection of specific causes e.g hypoxia, infection, malf’n
produce measurable benefits in reducing perinatal loss/injury
such system is likely to involve tests which assess several fetal systems, CVS, NS,, RS and use >1 modality
Factors for increased fetal risk
• Medical complications:
HTN, DM, AID, Hb pathies
• Fetal problems:
IUGR, Non-lethal anamolies, prematurity, postdatism, hydrops
• IU problems:
Bleeding, fever, meconium stain, oxytocin augment.
Utero-placental complex
•Uterus depends on placenta for diffusion of nutrients and respiratory gas exchange.
•Placental function depends on uterine blood flow (UBF)
•Uterine contraction leads to transient decreased UBF
•Borderline placenta may lead to fetal asphyxia during L&D
•Fetal compensatory responses limit the damage
•Prolonged or severe hypoxia may cause injury or death.
Non-invasive:
Fetal Movement Count:
Fetal Heart Recording….. CTG
Biophysical Profile {BPP} scoring
Doppler studies
Invasive:
• Chorion villus Sampling
•Amniocentesis
•Umbilical artery canulation
Intrapartum Fetal Assessment
• Electronic Fetal Heart Monitoring
• Fetal Scalp pH ( and pCo2, pO2) Monitoring
• Fetal Scalp Stimulation
• Vibroacoustic Stimulation
• UA Velocimetry and Biophysical profile
• Fetal Pulse Oximetry
• Near-infrared Spectroscopy
Screening tool to assess the fetal state of oxygenation and predicts early signs of hypoxia and fetal distress.
• Stimulus: Contractions/ fetal movements
• Baseline fetal heart rate
• Baseline variability
• Accelerations
• Decelerations
baseline heart rate
Baseline variability
Classification:
Silent 0-5 bpm
Reduced 6-10 bpm
Normal 11-25 bpm
Saltatory >25 bpm
accelerations
Decelerations:
Decelerations:
Basal fetal oxygenation. The relationship of late decelerations to baseline fetal oxygenation during contractions
Signature +
Date & Time
DEFINE
RISK
CONTRACTIONS
BASELINE
RATE
VARIABILITY
ACCELERAT’N
DECELERAT’N
OVER ALL ASSESSMENT
• Baseline Rate 110-150 bpm
• Amplitude of baseline variability 5/10-25 bpm
• Absence of decelerations, except for fleeting& short
• Presence of 2 or more accelerations during a 20 min period
• Baseline rate of 150-170 bpm/ 100-110 bpm
• Amplitude of variability bn 5-10 bpm > 40 min
• Increased variability above 25 bpm {saltatory}
• Absence of accelerations for > 40 min
• Sporadic decelerations of any type, unless severe
• Baseline heart rate < 100 bpm or > 170 bpm
• Variability < 5 bpm for > 40 min
• Recurrent decelerations of any type
• Severe variable or late decelerations
• A sinusoidal pattern
Any of the following:
Indications of use:
pregnancy location
viability
fetal number
dating
anomaly
placental localization, amniotic fluid
fetal growth and wellbeing
during invasive procedures
Assessment of gestational age and fetal growth:
menstrual history unreliable in up to 45% of women
serial fundal height measurement provides a guide to fetal growth
USS: crown-rump length before 14 weeks
USS: BPD serial measurement every 2 weeks for fetal growth. Unreliable after 28 weeks for dating
USS: head/abd ratio, 2 weeks serial HC & AC for fetal growth .. IUGR AC< but initially HC ~.
USS: femur length, more precise guide to gestational age than BPD
Serial measurements are necessary to identify the growth pattern and detect any lag in the growth and IUGR
Biophysical ProfileBiophysical Profile& &
Color Doppler ultrasound Color Doppler ultrasound
in the high risk pregnancyin the high risk pregnancy
•BPP is applying to detect prenatal
asphyxia
•Doppler ultrasound is a modality for
detecting fetal hypoxia and acidosis
•Doppler can also predict later pre-
eclampsia at the 24-26 gestational weeks.
•Hypoxia: Low Oxygen tension
•Asphyxia: Low Oxygen and high CO2
•Ischemia: Drop in blood flow
BPP uses FHR monitor and real time USS to assess:
fetal breathing movement
discrete body or limb movement
fetal tone
FHR
amniotic fluid volume
Amniotic fluid volume is most important
Fetal breathing movement is the first to disappear in asphyxia
7 days reassurance in low risk, only 24 hours in high risk preg
ComponentComponent DefinitionDefinitionFetal movements3 body or limb movements
Fetal toneOne episode of active extension and flexion of the limbs; opening and
closing of hand
Fetal breathing movement
episode of >= 30 seconds in 30 minutes Hiccups are considered
breathing activity.
Amniotic fluid volumesingle 2 cm x 2 cm pocket is considered adequate.
Non-stress test2 accelerations > 15 beats per minute of at least 15 seconds duration.
commentcomment
•As you know, oligohydramnios may be
• Mild AFI=5-8cm
•Moderate AFI=2-5cm
•Sever AFI<2cm
only sever oligohydramnios is considered as an
abnormal score.
•Fetal movement and fetal tone develop
between 7.5 and 9 weeks’ menstrual age
•Fetal breathing movements are
detectable by, at least 17-18 weeks’
gestation
•The non-stress test is most reliable
between 32 weeks and term (Ware, 1994).
An early stage in fetal adaptation to hypoxemia
-central redistribution of blood flow (brain-sparing reflex)
-increased blood flow to protect the brain, heart, and adrenals
-reduced flow to the peripheral and placental circulations
Umbilical arteryUmbilical artery
Clinical Indications for Doppler Studies
most useful in assessing IUGR
identify only the sub-group which is hypoxemic bec/of inadequate placental function and may be abnormal for up to 18 weeks before any fetal problem is observed
no proven role in population screening for increased risk of pre-eclampsia or IUGR
Recommended