Between 5% to 8% of pregnant women will develop gestational diabetes and this usually occurs around the 24th to 28th week of pregnancy. Gestational diabetes is a type of diabetes that affects only pregnant women. It shows up in women who’ve never had diabetes before. And for many (but not all) such women, it goes away on its own after their babies are born.
In pregnancy, the placenta (the blood source for the baby) produces hormones that help the baby grow and develop. Some of these hormones block the action of the mother’s insulin which is called insulin resistance. During pregnancy, to keep the blood glucose levels normal, mothers need to make 2 to 3 times the normal amount of insulin due to this insulin resistance. If the body is unable to produce the extra insulin or becomes more resistant, gestational diabetes develops. When the baby is born and the insulin requirements fall, glucose levels return to normal and diabetes usually disappears.
Most pregnant women don’t have signs of gestational diabetes. This is why screening tests are so important, usually between 24th and 28th weeks of pregnancy. The test checks your blood sugar levels after a glucose load.
Some pregnant women do notice clear signs of gestational diabetes. The symptoms are similar to those of other diabetes forms. But they are also common symptoms in all pregnant women, so they are easy to miss as the sign that something’s wrong. Symptoms of gestational diabetes include:
1. Feeling thirsty / drinking excess water
2. Urinating more than usual
5. The tummy looks bigger
6. Infection bladder, Vagina and Skin
7. Being tired / fatigue
Gestational diabetes is diagnosed with blood tests. Most pregnant women are tested between the 24th and 28th weeks of pregnancy, but if you have risk factors, your doctor may decide to test earlier in the pregnancy. Some women are at high risk of developing this condition.
The Risk Factors include :
1. Overweight/obesity or BMI > 30 kg/m 2 (pre-pregnancy or on entry to care)
2. Excessive weight gain in pregnancy
3. Family history of DM (first degree relative or sister with GDM)
4. Over 30 years of age or maternal age over 40 years
5. Previous history of GDM
6. Poor obstetric history – unexplained stillbirth, miscarriage or Previous perinatal loss
7. Previous large baby or babies or macrosomia (birth weight> 4500 g or > 90th percentile)
8. Ethnicity (some women from certain ethnic backgrounds are at higher risk)
9. Previous perinatal loss
10. Polycystic Ovarian Syndrome
11. Medications (corticosteroids, antipsychotics)
12. Multiple pregnancy
Blood testing confirms the diagnosis. If the screening test is not normal, you may need additional testing will generally be necessary.
OGTT (Oral Glucose Tolerance Test) as preferred test for diagnosis
One or more of:
1. Fasting ≥ 5.3 mmol/L (95 mg/dL)
2. 1 hour test ≥ 10 mmol/L (180 mg/dL)
3. 2 hours test ≥ 8.5 mmol/L (155 mg/dL)
4. 3 hours test ≥ 7.8 mmol/L (140 mg/dL)
HbA1c (if OGTT not suitable)
1. 1st trimester only
2. Result ≥ 42 mmol/mol (or 6.0%)
OGTT advice for women:
1. Fast (except for water) for 8-14 hours prior to OGTT
2. Take usual medications