thank you for your query,
The normal range of Vit B12 is 200 to 600, so results of your blood tests are considered low.
Vit B12 is essential for the normal functioning of brain, central & peripheral nervous systems and formation of blood.
As a result, deficiency of this Vitamin will affect the functioning of brain, cause abnormalities in nerve
conduction & also cause pernicious anemia
To prevent all these complications, your doctor has advised to take injections.
There is no need to worry, you will be fine after treatment & it will not have any impact on your child.
Also make sure that you are taking diet rich in Vit B12 like fish, meat, egg, milk & milk products, etc.
You can contact me for any follow up questions