Is it okay to drink Abbott similac mum maternal milk everyday? Will it contribute to GD?

Was told by gynae not to drink maternal milk due to high sugar content. Fresh milk is enough, just make sure u eat a balanced diet and don't forget the supplements tt gynae prescribed. My cousin who's known to be a health junkie who really takes care of her diet even before pregnancy, got GD, suspect it's due to the maternal milk tt she drank while for me, I still indulge in sweet drinks and desserts but don't drink any maternal milk, I have no GD. But of cz ur genes too may play a part.