Many times, gestational diabetes doesn't develop until later in the pregnancy, which is why they don't routinely test for it earlier (because for most women it wouldn't be a problem early in pregnancy). I had GD with previous pregnancies, so they tested me at 20 weeks - and if you've had GD previously, the drs should test early. If it's controlled, with diet or medication, then it poses very little risk to mother or baby. If not controlled, it can cause problems - but your dr should be able to help you control it by sending you to a specialist in GD (I'm seeing a perinatologist and a nutritionist).
at 12:49 PM on Apr. 25, 2010