Talk to Gynecologist on Unable To Control Gestational Diabetes

I am 28 weeks pregnant. This is my 2nd pregnancy. I went through From IUD in my first pregnancy in 32 weeks due to preclampsiya. Now in my current pregnancy i am diagnosed with gestational diabetes I am using Novomor insulin 10 points 3 times a day n 2 points of levemir insulin after evening meal. I am unable to control my sugar after 2 hours of breakfast and evening dinner. It ranges from 138 to 150 in both times. I am very much afraid due to my previous case kindly suggest me something do I increase points of insulin if yes then how much points should i increase. thankyou