Biophysical profile

Biophysical profileSamia Mohamad EidAssist. Prof of Obs & Gyne.Al-Azhar university

BPP is applying to detect prenatal asphyxiaDoppler ultrasound is a modality for detecting fetal hypoxia and acidosis.Hypoxia: decrease oxygen concentration in the tissue & blood.Acidosis increase concentration of H+ in tissue & blood. Asphyxia: hypoxia & metabolic acidosis.Ischemia: Drop in blood flowThe 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 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

In 1980, Maning and Platt fashioned a method forFetal surveillance in high risk pregnancy that combine FHR with various US variable

FHR monitoringFetal breathing movementFetal movementFetal toneAmniotic fluid assessmentBiophysical profileFetal 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 termSo ,BPP has a limited role for assessing fetal well being before 32 gestational weeks.

Comment Timeline for fetal hypoxia

So, Doppler ultrasound can predict fetal distress sooner than BPP

commentIt 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

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

Action generated in the ventral surface of the 4th ventricle .One episodes of 3oseconds during an observation period of up to 20 minutes.Prolonged hypoxia and/or acidemia blunt this activity. Fetal breathing

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 happeningDepends 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

Amniotic fluid assessment

Amniotic fluid relates indirectly to fetal brainBrain sparing concept Except post term pregnancyAssessment 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 42wsBasically there are 3 methods commonly used to assess the adequacy of AF:Vertical pocket technique.Amniotic fluid index.subjective (eyeball) assessment.Assessment of AFVertical pocket technique

1 cm oligohydramnios 2cm oligohydramnios

AFIAs you know, oligohydramnios may be Mild AFI=5-8cmModerate AFI=2-5cmSever AFI