How To Improve Fetus Growth?

My 7th month of pregnancy is going now my doctor scan an ultrasound she says that my baby is to week to anormal baby after reading report she says that baby seems 10 days week of my pregnancy time period she advice me to inject a drip for the normal growth of 7th month baby , i want to know is it necessary or not. and what can i do for the groth of my baby except this treatment