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How Do I Know If I Have Gestational Diabetes?

Women at risk for diabetes should get tested — preferably before pregnancy, or as soon as they know they are pregnant. Since most birth defects happen within the first three to six weeks after conception, it's important that diabetes be controlled even before you get pregnant.

Most cases of gestational diabetes develop late in pregnancy and are diagnosed during routine screening tests at 24 to 28 weeks of pregnancy.

Although some guidelines suggest that only women at risk for gestational diabetes be screened during pregnancy, it is likely that your healthcare provider will recommend you have a glucose challenge test between your 24th and 28th week of pregnancy, even if you are not at risk. You'll be given a very sweet drink containing exactly 50 grams of glucose (sugar). An hour after you've drunk this, a blood sample will be tested to determine your blood sugar level.

If your glucose challenge test comes out abnormally high (higher than 130 to 140 mg/dL), you'll be asked to return to the doctor's office for a slightly more involved test, called the glucose tolerance test. For this test, you may be given special dietary instructions to follow for several days before the test. You'll need to fast for 8 to 12 hours before the test. At the time of the test, you'll first have your blood tested to determine your fasting blood sugar level. Then you'll be given a drink containing exactly 100 grams of glucose. Your blood glucose will be tested one, two, and three hours later. The diagnosis of gestational diabetes is made if two or more values are abnormally elevated.

What Are the Treatments?
It's best if you consult a registered dietitian to help you design a reasonable diet plan — one that will address the gestational diabetes but still provide your growing baby with sufficient calories and nutrients. In addition to adjusting your diet, reasonable exercise (approved by your healthcare provider) four to five times a week also helps the body use insulin more efficiently, which helps control blood sugar levels.

Your dietitian will recommend the number of total daily calories appropriate for a woman your height and weight. About 2,200 to 2,500 calories per day is usually recommended for women of average weight. Overweight women may be asked to stick to diets of about 1,800 calories per day.

Your dietitian will teach you how to balance your diet, probably suggesting that about 10% to 20% of your calories come from protein sources (meats, cheeses, eggs, seafood, and legumes); less than 30% of your calories come from fats (with less than 10% of those from saturated fats); and the rest of your calories should be from carbohydrate sources (breads, cereals, pasta, rice, fruits, and vegetables).

To make sure the dietary adjustments and/or exercise are working properly for you, your blood sugar level may be tested regularly, before and/or two hours after meals, at your healthcare provider's office, or you may be taught to monitor your own blood sugar at home with a simple machine called a glucometer.

If your blood sugar levels remain elevated despite a special diet, you may be asked to give yourself insulin injections. Few women with gestational diabetes (about 10%) have to use insulin, though. Pregnant women are not able to take pills to control blood sugar due to the potential effects on the fetus.

Depending on how well the diabetes is controlled and how your pregnancy is progressing, your healthcare provider may monitor your baby more closely during the last weeks or months before your due date with ultrasounds, non-stress testing, and/or fetal movements charting. If the baby appears to be growing very large, you may be given an ultrasound test to try to verify your baby's size.

While most women with gestational diabetes are able to have a normal labor and vaginal delivery, some healthcare providers prefer to deliver the baby earlier than the due date or may even suggest a cesarean section if the baby becomes too large. This is an area of some controversy.

After delivery, your healthcare provider will check to make sure that your blood sugar levels have returned to normal. You'll need to have this re-checked about six weeks after delivery, and then at least every three years after that and some recommend annually.