A Growth Scan is normally done, between 28 – 32 weeks of pregnancy, to assess the growth of your baby and amount of liquor. It is a standard scanning procedure used to check the development of the baby in the third trimester.

A growth scan is very important to check the normal development of the foetus inside the womb.

A growth scan is used to check if the baby is healthy by monitoring the baby’s weight and various body measurements, to know about the position of the baby, determine the amount of amniotic fluid present, check the position and maturity of the placenta, check the position of the umbilical cord, check the wellbeing and circulation of the baby. It also gives an insight into how a previous caesarean scar looks. Monitoring of multiple pregnancies is also done through it.

The doctor asks the patient to lie on a couch and uncover the abdomen and applies gel on the abdomen. Then he/she passes a handheld probe over the skin of the abdomen. The gel is applied to make sure that there is good contact between the probe and the skin. As the probe moves, a black and white 2-D image of the baby will appear on the ultrasound screen. 

1. With the help of the image on the screen, the doctor will check how the baby is doing by checking the movement, breath, etc. and will rate the baby on a total score of 10 (Biophysical profile). A high number indicates that the baby is doing well whereas a lower score can suggest that the baby is not getting enough oxygen from the placenta.
2. The doctor also checks the baby’s head (HC) and abdomen (AC) circumference to check if the baby is growing healthily inside the womb or not. 
3. The position of the baby can be established whether it is breech, cephalic or transverse.
4. Measurement of the liquor can be done to assess the Amniotic fluid index. The scan would be required to be repeated more frequently if the baby is larger or smaller than expected; amniotic fluid is not in the normal amounts.
5. The position or maturity of the placenta can be assessed.
6. The length of the cervical canal and the internal os diameter can be assessed in cases of pain in the abdomen and previous history of preterm labour. 
7. To find out more about how the baby is doing, the doctor can perform a Doppler scan to see how well the placenta is working. This is done by measuring the flow of blood between the placenta and the baby. If the doppler study is abnormal there are chances of growth retardation of the baby.
8. In case you have had complications in your previous pregnancies, your doctor might advise a Growth scan as and when needed to closely monitor the health of the fetus.

Though these scans are perfectly safe and do not have any side-effects, your doctor may only advise you to get one done if he suspects something is amiss.