After I have my baby, how can I find out whether my diabetes is gone?

You will probably have a blood glucose test 6 to 12 weeks after your baby is born to see whether you still have diabetes. For most women, gestational diabetes goes away after pregnancy. You are, however, at risk of having gestational diabetes during future pregnancies or getting type 2 diabetes later.

source: http://diabetes.niddk.nih.gov/dm/pubs/gestational/index.htm