My doc suggested betamethasone injection 3impule in one injection n should repeat after 24hours isnt it very heavy dose for fetal as i feel numbness?

Yes: Betamethasone is injected every 24 hours for two doses to help your baby's lungs and brain mature. Usually this is prescribed when a physician is worried about the baby being delivered early and the risks of prematurity out weigh the risks of the steroid injection.

Appropriate: This is pretty standard for someone who is likely to deliver prematurely. It helps the baby's lungs mature and may also protect the brain in premies.