Fetal Growth and Well-Being Ultrasound
Sometimes the need to assess fetal growth and well-being arises in the late second or third trimester of pregnancy. Reasons for referral may include previous complications of pregnancy, maternal medical conditions e.g. diabetes or if there is a clinical question e.g. small for dates. Multiple factors are assessed:
· Fetal presentation (cephalic, breech, transverse)
· Placental position
· Fetal size and growth interval
· Fetal heart rate and rhythm
· Amniotic fluid around the fetus
· Fetal activity
· Analysis of blood flow in the umbilical artery (further assessment of blood flow in the fetal brain and liver is performed if indicated)
· Review of uterine fibroids and ovarian masses if required
Fetal size can be assessed by measuring four parameters:
· Biparietal diameter (BPD)
· Head circumference (HC)
· Abdominal circumference (AC)
· Femur length (FL)
These measurements are plotted on a growth chart and an estimate of fetal weight can be made.
To assess fetal growth, serial scans may be performed to assess progression on the growth chart.
If fetal growth measurements are not average or there is maternal medical conditions assessment of the umbilical artery is made to assess the resistance of the blood flow into the placenta.
If the fetus is smaller than expected or there is question over placental function, assessment of the Middle Cerebral Artery (fetal brain) and ductus venosus (vein in fetal liver) may be performed. Further evaluation of the Middle cerebral artery will occur if there is suspicion of anaemia.
At Ultrasound North we perform ultrasounds for a clinical indication – however 3D/4D imaging will be attempted, quality limited by fetal cooperation .