I refused it with DD3. I have no family history of GDD and I had never had it with any of my other pregnancies, so I figured there was a bigger chance of me not having it than having it.
I never wanted to have it with DS2 & DD2 but felt rather forced into having it. I get headaches and feel very nauseated after the drink too. I was happy to have not had it done and there was never an issue with me not having it.