Most women who are diagnosed with gestational diabetes don't have any symptoms. That's why your healthcare provider will offer you a screening test for gestational diabetes when you're between 24 and 28 weeks pregnant.

If you have any risk factors for gestational diabetes, your provider may suggest doing the test earlier. Most women who have gestational diabetes find out that they have it after taking this test.

The most common test for gestational diabetes is the oral glucose screening test. This test measures how efficiently your body produces insulin. On the day of the test, your provider will give you a sweet liquid to drink. An hour later, you'll have a blood test to check your glucose levels.

If your test shows that your blood sugar is too high, you'll have to take a longer test called the oral glucose tolerance test. For this test, you'll need to fast before being given a sweet liquid to drink. Your blood will be tested at fasting, then again after one, two, and three hours. If the result of two tests shows your blood sugar is too high, you'll be diagnosed with gestational diabetes.

Both of these tests are safe for you and your baby and don't have any major side effects. But drinking the liquid may taste unpleasant and make you feel nauseated afterward.