It would depend on who you were put under after you've had your baby...
It depends on who your diabetic care was transferred to... If you remained under the diabetic consultant/clinic care they should have been monitoring you with follow-up appointments etc... Due to clinical records the consultant may or may not choose to carry out another GTT.. (I didn't get one)
But if you are transferred back under the GP care they should have called for a GTT at the same time as your 6 week post natal check...
My son was born 22 years ago today... It was at the beginning of this pregnancy I was diagnosed (same phone call confirming both) put straight onto insulin for the duration of the pregnancy, told it's likely to be GD yeah right, My diabetic consultant insisted that I was T2 when insulin was withdrawn after I had my son, and my BG's were going up... Stuck me on Metformin.. Wouldn't change his mind for several years (had another baby exactly 18 months to the day later) it wasn't until I was extremely ill, and my GP transferred me out of the diabetic clinic to another Endo's consultants clinic that I was finally diagnosed as T1 diabetic (slow onset)...
Looking back now, yes in many ways I very angry with my first diabetic consultant, as not only because I suffered medical, but what impact and what it did to my life during this time...
Now I don't look back it's not worth feeling angry about it all...