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anomaly scan or mid pregnancy scan as it is sometimes called is ideal
for those parents looking for reassurance or as a secondary option when
an earlier screening test has not been performed. Furthermore, it
provides an added opportunity to assess the baby’s well being. Your
baby’s internal organs are examined in cross section which may be
difficult for you to make out. Bones appear white, fluid is black and
soft tissues may seem to be varying degrees of grey. At
this time we will check for soft markers which are changes in the
normal anatomy and may indicate an abnormality. The four most common
markers are choroid plexus cysts, renal pelvic dilatation, echogenic
bowel and an echogenic foci attached to the muscle of the heart. It is
important to understand that although these can be seen in affected
pregnancies they can also be seen in normal healthy babies. If you had
screening earlier in your pregnancy e.g. NT then the presence of any
soft markers later in pregnancy are even less likely to be of any
significance. The baby’s head is
examined for shape and size. Internal structures such as the ventricles
of the brain and cerebellum are examined. The sonogrpaher will do
standard measurements and look at the baby’s lips and nose for any
obvious defects. The spine is
assessed in both long and short axis views to make sure that all of the
vertebrae are in alignment and that the skin is closed. The baby’s
abdominal wall is checked at this time too to make sure that all of
abdominal organs are in their correct position. 90% of all abdominal
wall and spine defects can be picked up by ultrasound. The
chest is assessed to view a four chamber foetal heart and to check its
size and shape. The two atria should be equal in size and the two
ventricles should equal in size. This rules out 90% of fetal heart
defects. If the baby is in a good position the main vessels will also
be assessed at this time. The stomach
and bladder are also imaged. The baby swallows some of the amniotic
fluid that it lies in and so some of that fluid will be seen as a black
bubble in the stomach and the urinary bladder as well. Yes, the baby
has a wee inside about every half hour so the urinary bladder fills and
empties during the scan. Baby’s legs, arms, hands and feet are examined. The umbilical cord is assessed to make sure there are three vessels. The placenta will be documented to lie anteriorly or posteriorly and to ensure that the placenta does not cover that cervix. There should be enough amniotic fluid at this stage to allow baby to move around freely.
Procedure
Includes: Standard dating measurement & report with b/w print.
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