Pregnancy and preterm labor

Hello! Does anyone have experience using the medication Makena to prevent preterm delivery? I am currently 15 weeks pregnant with my third child. The first was born at 36w 4d and the second at 34w 2d. This time my high-risk OB is suggesting I try Makena shots to prevent preterm delivery and says “theoretically” the shots should not increase my blood sugar however she could not think of any type 1 patients she had used it with. I am nervous to give myself anymore medication and possibly make my already difficult sugars even harder to control. Any advice would be appreciated!!