Samia Mohamad Eid Assist. Prof of Obs & Gyne. Al-Azhar
university
Slide 2
BPP is applying to detect prenatal asphyxia Doppler ultrasound
is a modality for detecting fetal hypoxia and acidosis.
Slide 3
Hypoxia: decrease oxygen concentration in the tissue &
blood. Acidosis increase concentration of H+ in tissue & blood.
Asphyxia: hypoxia & metabolic acidosis. Ischemia: Drop in blood
flow
Slide 4 > carbon dioxide + water + energy Poor blood flow
from"> > carbon dioxide + water + energy Poor blood flow from
the uterus and placenta causes the fetus to constrict blood vessels
in nonvital peripheral areas in order to supply more blood flow to
vital organs such as the heart and brain. How hypoxia leads to
acidosis"> > carbon dioxide + water + energy Poor blood flow
from" title=" The fetus uses oxygen to "burn" molecules and release
energy. The reaction: glucose + oxygen >> carbon dioxide +
water + energy Poor blood flow from">
The fetus uses oxygen to "burn" molecules and release energy.
The reaction: glucose + oxygen >> carbon dioxide + water +
energy Poor blood flow from the uterus and placenta causes the
fetus to constrict blood vessels in nonvital peripheral areas in
order to supply more blood flow to vital organs such as the heart
and brain. How hypoxia leads to acidosis
Slide 5
With a limited supplies of oxygen (hypoxia) the peripheral
tissues can only partially break down the sugar and converts it to
lactic acid. Significant levels of acid in the blood (acidemia) may
suppress the fetal nervous system and eventually lead to
cardiovascular collapse. How hypoxia leads to acidosis
Slide 6
In 1980, Maning and Platt fashioned a method for Fetal
surveillance in high risk pregnancy that combine FHR with various
US variable
Slide 7
FHR monitoring Fetal breathing movement Fetal movement Fetal
tone Amniotic fluid assessment Biophysical profile
Slide 8
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
Slide 9
So,BPP has a limited role for assessing fetal well being before
32 gestational weeks. Comment
Slide 10
Timeline for fetal hypoxia
Slide 11
So, Doppler ultrasound can predict fetal distress sooner than
BPP comment
Slide 12
It involve the ability of the hypothalamus and medulla to
maintain a variable, rather than smooth baseline and to increase
the heart rate with fetal movement. Hypoxia or acidosis decrease
beat-to-beat variability and accelerated FHR with fetal activity.
FHR monitoring
Slide 13
Fetal breathing movements are detectable by, at least 17-18
weeks gestation. After 30ws of gestation, the fetus will spend
about 30%of his time making breathing motion. Fetal breathing
Slide 14
Action generated in the ventral surface of the 4 th ventricle.
One episodes of 3oseconds during an observation period of up to 20
minutes. Prolonged hypoxia and/or acidemia blunt this activity.
Fetal breathing
Slide 15
The fetal cortex generate the massage for the fetus to move
his/her arms, legs, trunk. At least 3 trunk movements during 20
minutes observation period. Fetal movement Profound hypoxia and
Acidemia will stop this for happening
Slide 16
Depends on intact cortex and subcortex. One episode of
extension with a return to flexion during--------. Is the last to
go in a sequence of events ending in severe fetal compromise.
Actually, fetal tone is the least useful variable since, By the
time tone is lost, all of the other categories will have had scores
zero (unless ---------------?) Fetal tone
Slide 17
Amniotic fluid assessment Amniotic fluid relates indirectly to
fetal brain Brain sparing concept Except post term pregnancy
Slide 18
Assessment of AF. AF volume rise linearly to about 33-34ws when
the average is about 1000cc. After which it generally drops slowly
to about 800cc at 40 ws and to 600cc at 42ws AF volume rise
linearly to about 33-34ws when the average is about 1000cc. After
which it generally drops slowly to about 800cc at 40 ws and to
600cc at 42ws
Slide 19
Basically there are 3 methods commonly used to assess the
adequacy of AF: 1.Vertical pocket technique. 2.Amniotic fluid
index. 3.subjective (eyeball) assessment. Assessment of AF
Slide 20
Vertical pocket technique 1 cm oligohydramnios 2cm
oligohydramnios
Slide 21
AFI
Slide 22
As you know, oligohydramnios may be Mild AFI=5-8cm Moderate
AFI=2-5cm Sever AFI