monitoring of the fetal heart Flashcards
how does acute placental insufficiency happen ?
suddenly occurs with an otherwise normal fetus leading to acute fetal distress such as in cord accidents and placental separation
what is the end result or consequence of chronic placental insufficiency ?
small for gestational age
what are the placental function tests ?
daily fetal movement count non stress test fetal biophysical profile doppler color flow studies oxytocin challenge test
what blood vessels are checked using the doppler ?
ductus venosus
umbilical artery
middle cerebral artery
what does the fetal biophysical profile include ?
breathing movement total body movement tone AFI CTG
what does the modified BPP include ?
AFI plus NST
what does high resistance in the doppler suggest ?
placental insufficiency
what does low resistance in doppler indicate ?
hypoxia due to brain sparing phenomenon
what does absent or reversed end-diastolic flow in the umbilical artery indicate ?
severely compromised fetus
what does a positive OCT test indicate ?
FHR decreases with oxytocinn administration
what does a negative OCT test indicate ?
No FHR changes in response to contractions which indicates good fetal well being
what are the maternal risk factors that could cause fetal hypoxia ?
previous CS pre-eclampsia post term pregnancy prolonged membranes rupture induced labour diabetes antepartum hge
what are the fetal risk factors for hypoxia ?
small for gestational age prematurity oligohydraminous abnormal doppler multiple pregnancies meconium
how can meconium cause fetal distress ?
through aspiration pneumonia
what are the intra-partum risk factors ?
oxytocin augmentation hypertonic uterus epidural analgesia vaginal bleeding maternal pyrexia fresh meconium Abnormal FHR
in active labour how can fetal heart monitoring be performed in low risk and high risk patients ?
low risk - pinard and sonicaid
High risk - CTG and FBS if needed
how often should FHR be assessed in the first stage of labour and in the second stage ?
first stage every 15 mins
second stage every 5 mins
what is the normal baseline fetal heart rate ?
110-160 bpm
at what FHR do we diagnose bradycardia and tachycardia ?
bradycardia : <110 bpm
tachycardia : > 160 bpm
at what FHR do we consider the tachycardia and bradycardia to be pathological ?
pathological tachy : more than 180 bpm
pathological brady: less than 100 bpm
what are the values for :
normal beat to beat variability
non-reassuring
pathological ?
normal: 5-25 bpm
non-reassuring: less than 5 for 30 to 50 minutes
or
more than 25 bpm for 15-25 minutes
pathological: less than 5 bpm for more than 50 minutes
or more than 25 for more than 25 minutes
what is acceleration ?
increase in FHR by 15 bpm for longer than 15 seconds
what is deceleration ?
a transient decrease in FHR by at least 15 bpm for more than 15 seconds
what are the types of deceleration ?
variable and non variable
what are the different types of non variable deceleration ?
non variable declaration : early and late
what is early deceleration ?
uterine contractions and the decelerations occur at the same time on the CTG strio
what is early deceleration a sign of ?
head compression, which means the mother is in labour and is a good sign
what is late deceleration ?
the declaration happens after the uterine contraction , this is usually not a good sign
what is late deceleration an indication of ?
uteroplacental insufficiency
what is variable deceleration ?
uterine contractions and decelerations are not related to each other
what is variable deceleration a sign of ?
cord compression
what are efficient uterine contractions defined as ?
3 contractions in 10 minutes and each contraction should last more than 40 seconds each
what is the RCOG classifications of CTG ?
normal = all 4 features are reassuring suspicious = one non reassuring feature pathological = one abnormal pattern or 2 non reassuring features
when would there be a need for urgent intervention ?
if there is an acute onset of bradycardia or 1 single prolonged deceleration lasting more than 3 minutes
what is sinusoidal rhythm an indication off ?
severe fetal anemia ( must be lasting at least 10 minutes)
