antepartum assessment of fetal wellbeing

ANTEPARTUM ASSESSMENT OF FETAL WELLBEING
The obstetrician is responsible for 2 patients during pregnancy and labor, one of them being the fetus. The hidden patient is guarded by the following barriers:
Anatomical: which can be overcome to some extent by U/S imaging.
Physiological: these need an understanding of the interaction between fetal and maternal physiology.
Fetal assessment begins in the 1st trimester by the confirmation of viability and determining the gestational age.
In the 2nd trimester the fetus should be evaluated by its genetic and structural development.
In the 3rd trimester the assessment involve the evaluation of fetal growth and wellbeing in anticipation of labor.
Determination of the GA of the fetus and confirmation of its viability, exclusion of congenital anomalies (in high risk mothers of having congenital anomalies) by biochemical screening tests, and nuchal translucency by U/S are done in the 1st TM.
In the 2nd TM *Routine anomaly U/S scanning at (18-20) weeks is done.
In the 3rd trimester: A major risk to the continuation of normal fetal development is believed to occur when the increasing fetal requirement for growth is no longer obtained (secondary to uteroplacental insufficiency).
Fetal monitoring during the 3rd trimester aims to recognize this reduction in placental function by identifying alteration in fetal growth, placental perfusion, liquor volume, fetal movement and / or fetal heart rate.
The most widely used tests of fetal wellbeing in late pregnancy are:
1- Antenatal cardiotocography (CTG).
2- Biophysical profile.
3- Doppler U/S.