HI I Am 32 Weeks Pregnant And My Doppler Showed

HI I am 32 weeks pregnant and my Doppler showed less amniotic fluid and uterine arterial pressure and got ANA positive test. My doctor started me on IV medications and bed rest and advised me lonopin injections 20 mg daily subcu. What are its benefits and side effects. Will it help my pregnancy as this is my first pregnancy and there is no family history of miscarriage. Does it cause any side effects to me or my baby in the future. Please do help me withe the query.