Q: I am a 34 years old pregnant woman who had a O'Sullivan test done, which showed fasting blood sugar level at 0.82 g/l (4.55 mmol/l). After 1-hour absorption of 50 g glucose, the levels were at 1.34g/l (7.43 mmols), respectively. I was told that a result > 7.8 mmols is positive, although I have found evidence in some studies that > 1.3g/l is considered positive also, but sometimes result below 1.4 g/l is not positive. I was tested 2 days before my 32nd week of pregnancy. Do I have diabetes or not? Also, is it normal for this test to be carried out between 24 and 28 weeks pregnancy, so is the result even relative? As it seems to be borderline, is there another test that can be carried out that would be more conclusive? Please advise.

A:Screening for gestational diabetes is usually performed between 24 and 28 weeks of pregnancy. Test (screening) On the day of the screening test, the woman may eat and drink normally. She will be given 50 grams of glucose; this should be consumed within a few minutes. One hour later, a small sample of blood is drawn to measure the woman’s blood glucose level. The definition of elevated blood glucose; most consider a value greater than 130 to 140 mg/dL (7.2 to 7.7 mmol/L) to be elevated. The one-hour glucose test is a screening test, meaning that not everyone who has an elevated one-hour blood glucose level will have gestational diabetes. However, if the one-hour blood glucose level is very high (>=200 mg/dL [11.1 mmol/L]), many clinicians do not perform any further testing because there is a very good chance that the woman has gestational diabetes. Further testing — The three hour oral glucose tolerance test (GTT) is used to determine with certainty if a woman has gestational diabetes. The test is done by measuring the woman’s blood glucose level before she eats anything in the morning (fasting), then again one, two, and three hours after she drinks a glucose drink that contains 100 grams of glucose (twice the amount in the one hour test). Similar to the one-hour test, this is usually in the form of a specially formulated orange or cola drink. Recommendation is administering a three-hour 100-g oral GTT and using the criteria proposed by the Fourth International Workshop-Conference on Gestational Diabetes, whereby GDM is present if two or more of the following serum glucose values are met or exceeded -

1. Fasting serum glucose concentration >95 mg/dL (5.3 mmol/L)
2. One-hour serum glucose concentration >180 mg/dL (10 mmol/L)
3. Two-hour serum glucose concentration >155 mg/dL (8.6 mmol/L)
4. Three-hour serum glucose concentration >140 mg/dL (7.8 mmol/L)

I can not comment exactly on your test as units are mentioned is bit confusing and tests results are not clear but if your 1 hour after 50 gm of glucose is more than 130 mg/dL than get 3 hrs GTT. You have a risk of diabetes, as you are overweight. You should also get HBA1c done, which can help clinician. General dietary advise for gestational diabetes includes:

• The number of calories recommended depends upon the woman’s current and pre pregnancy weight.
• Avoid high calorie snacks and desserts, including soda, fruit punch, candy, chips, cookies, cakes, and full-fat ice cream.
• There is no evidence that use of artificial sweeteners such as aspartame (Nutrasweet®), sucralose (Splenda®), stevioside (Stevia®), or saccharin (Sweet N Low®) during pregnancy increases the risk of birth defects.
• Eat a lot of vegetables and fruits, at least five servings a day. Some fruits (e.g., grapes, dried fruit) can increase the blood glucose level significantly and should be eaten in limited amounts. Limit starchy vegetables (e.g., potatoes) but eat as many non-starchy fruits or vegetables as desired.
• Choose foods with whole grains rather than processed grains. Consider whole wheat bread, brown rice, or whole-wheat pasta instead of white bread, or maida based product white rice, or regular pasta.
• Eat a limited amount of red meat, and choose lean cuts of meat that end in loin
• Choose low or fat-free dairy products, such as skim milk, non-fat yogurt, and low-fat cheese.
• Use liquid oils (olive, canola) instead of solid fats (butter, margarine, shortening) for cooking.