Outlined below is the protocol of the examination of the pregnancy
in the second and third trimesters. This can be used as an
aide-memoire.
Confirm that there is a live pregnancy by
identifying the heartbeat
Establish the lie of the fetus and
identify the presenting part
Identify the fetal head and modify
the position of the probe to produce an axial
plane
Measure the biparietal diameter
and:
In the second trimester, use a dating
chart to estimate fetal age
In the third trimester, plot the growth of the
BPD on a growth chart
Measure the abdominal diameter in
axial section, calculate the abdominal circumference and plot the
measurement on the chart
Measure the length of the femur
and plot on the chart
Identify the position of the
placenta and:
In the third trimester, assess its
relationship to the internal os. Where appropriate, measure the
distance between the lower end of the placenta and the internal
os
Assess the volume of amniotic
fluid and where appropriate measure the maximum depth of
fluid (MVP)
Assess the anatomy of the fetus in order to
detect major fetal abnormality. This is especially
important if there is an abnormality of fluid
volume