Gestational diabetes isn't an immediate threat to your health. However, poorly controlled diabetes in pregnancy puts you at a higher risk of various problems. These include a condition called pre-eclampsia, which causes high blood pressure; premature labour; having too much amniotic fluid(the fluid around your unborn baby). If you have gestational diabetes, you're more likely to need a caesarean delivery than women who don't have diabetes. You're also more likely to develop gestational diabetes in future pregnancies and at a higher risk of developing type 2 diabetes later in life.
Attribution: BUPA