The growth of the baby is monitored after 28 weeks. At this time, the fetal head, abdomen and femur are measured and plotted on a graph to assess the growth. The exact timing of the scan is decided by the attending obstetrician or after the result of the previous scan. In “low risk” pregnancies, the scan may be done between 34-36 weeks and in high risk pregnancies the scan may be done around 28 weeks and follow up scans thereafter.
During this 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 study may be indicated to study blood flow to the baby
Performing the scan requires skill and concentration, so the sonologist may be quiet and not communicate with you for short periods of time, which is entirely normal. After the initial checks and measurements are completed, the baby will be shown on the screen and the parts explained. Please feel free to ask any questions you may have. The time taken for the scan is variable depending on visibility, 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 the same day or another day. This is a normal process which is done to ensure quality. The sonologist will explain the reason why she/he recommends a repeat scan and will arrange an appointment.
