Gestational Diabetes Testing; Necessary?

Let me preface this by saying I have a HUGE fear of needles. It is the one thing that kept me from wanting to ever get pregnant because I knew it came with a lot of needles. Nevertheless, I am now pregnant (and mostly loving it) but haven’t had to have any blood work done yet (was able to combine the first two and push it off as I am low risk).

That being said, I am aware that I can decline any and all tests but I also need to balance what is best for me might not be best for baby.

My question is, how necessary is the testing for gestational diabetes? I want to be a little more informed before I talk to my midwife.