The growth of the baby is monitored between 32–36 weeks. At this time, the fetal head, abdomen and femur are measured and plotted on a graph to assess the growth. During the scan, a detailed evaluation of all the organs and limbs may be difficult due to fetal position and relatively less space around the baby. In some situations, a Doppler may be indicated to study blood flow to the baby.
The time taken for one scan is variable depending on visibility of the fetal position, presence or absence of abnormalities. In some cases, the fetus would need to be seen by more than one operator and if necessary on another day. This is a normal process which is done to ensure quality.
In most uncomplicated pregnacies, a single growth scan is often done around 32 weeks to assess size of the fetus and its well being. In some conditions serial scans may be done to assess if the baby is growing well. Here a Doppler is often done to assess the bood flow to the baby.