Ok sarah here's what I have...
GD is caused by normal changes to your metabolism that promote foetal growth. A pg hormone (HPL) diminishes the effects of insulin. Treatment is usually a special diet, regular exercise and, in some cases insulin injections. Labour may be induced near term (this occured with one of my sisters two pg's) if excessive growth of bub is suspected or is placental circulation appears affected by GD.
Management of GD may reduce the risks of problems for the baby, such as, an overly large baby, hypoglycaemia, newborn jaundice and delayed lung development.

I hope that helps and isn't to scary for you

Tanya